I may or may not be having the same problem. On IRC JordanU gave some help.  Here's my data:


thufir@dur:~$ 
thufir@dur:~$ ps -ae | grep fire
12557 ?        01:58:10 firefox <defunct>
thufir@dur:~$ 
thufir@dur:~$ ps -p 12557 -o ppid
 PPID
    1
thufir@dur:~$ 
thufir@dur:~$ ps aux
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root         1  0.0  0.0   3620  1776 ?        Ss   May11   0:01 /sbin/init
root         2  0.0  0.0      0     0 ?        S    May11   0:00 [kthreadd]
root         3  0.0  0.0      0     0 ?        S    May11   1:02 [ksoftirqd/0]
root         5  0.0  0.0      0     0 ?        S    May11   0:00 [kworker/u:0]
root         6  0.0  0.0      0     0 ?        S    May11   0:00 [migration/0]
root         7  0.0  0.0      0     0 ?        S    May11   0:00 [watchdog/0]
root         8  0.0  0.0      0     0 ?        S<   May11   0:00 [cpuset]
root         9  0.0  0.0      0     0 ?        S<   May11   0:00 [khelper]
root        10  0.0  0.0      0     0 ?        S    May11   0:00 [kdevtmpfs]
root        11  0.0  0.0      0     0 ?        S<   May11   0:00 [netns]
root        12  0.0  0.0      0     0 ?        S    May11   0:00 [sync_supers]
root        13  0.0  0.0      0     0 ?        S    May11   0:00 [bdi-default]
root        14  0.0  0.0      0     0 ?        S<   May11   0:00 [kintegrityd]
root        15  0.0  0.0      0     0 ?        S<   May11   0:00 [kblockd]
root        16  0.0  0.0      0     0 ?        S<   May11   0:00 [ata_sff]
root        17  0.0  0.0      0     0 ?        S    May11   0:00 [khubd]
root        18  0.0  0.0      0     0 ?        S<   May11   0:00 [md]
root        21  0.0  0.0      0     0 ?        S    May11   0:00 [khungtaskd]
root        22  0.0  0.0      0     0 ?        S    May11   1:22 [kswapd0]
root        23  0.0  0.0      0     0 ?        SN   May11   0:00 [ksmd]
root        24  0.0  0.0      0     0 ?        SN   May11   0:00 [khugepaged]
root        25  0.0  0.0      0     0 ?        S    May11   0:00 [fsnotify_mark]
root        26  0.0  0.0      0     0 ?        S    May11   0:00 [ecryptfs-kthrea]
root        27  0.0  0.0      0     0 ?        S<   May11   0:00 [crypto]
root        36  0.0  0.0      0     0 ?        S<   May11   0:00 [kthrotld]
root        38  0.0  0.0      0     0 ?        S    May11   0:00 [scsi_eh_0]
root        39  0.0  0.0      0     0 ?        S    May11   0:00 [scsi_eh_1]
root        40  0.0  0.0      0     0 ?        S    May11   0:00 [kworker/u:3]
root        42  0.0  0.0      0     0 ?        S<   May11   0:00 [binder]
root        62  0.0  0.0      0     0 ?        S<   May11   0:00 [deferwq]
root        63  0.0  0.0      0     0 ?        S<   May11   0:00 [charger_manager]
root        64  0.0  0.0      0     0 ?        S<   May11   0:00 [devfreq_wq]
root       210  0.0  0.0      0     0 ?        S    May11   0:00 [scsi_eh_2]
root       213  0.0  0.0      0     0 ?        S    May11   0:00 [scsi_eh_3]
root       226  0.0  0.0      0     0 ?        S<   May11   0:00 [kdmflush]
root       228  0.0  0.0      0     0 ?        S<   May11   0:00 [kdmflush]
root       243  0.0  0.0      0     0 ?        D    May11   0:26 [jbd2/dm-0-8]
root       244  0.0  0.0      0     0 ?        S<   May11   0:00 [ext4-dio-unwrit]
root       475  0.0  0.0   2820   652 ?        S    May11   0:00 upstart-udev-bridge -
root       477  0.0  0.0   3520   980 ?        Ss   May11   0:00 /sbin/udevd --daemon
root       698  0.0  0.0   2816   408 ?        S    May11   0:00 upstart-socket-bridge
root       766  0.1  0.0      0     0 ?        S    May11   1:29 [flush-252:0]
root       833  0.0  0.0   5492   760 ?        Ss   May11   0:00 dhclient -1 -v -pf /r
103        978  0.0  0.0   3932  1676 ?        Ss   May11   0:03 dbus-daemon --system 
root      1027  0.0  0.1   7416  2032 ?        Ss   May11   0:00 /usr/sbin/modem-manag
root      1028  0.0  0.0   4784  1412 ?        Ss   May11   0:00 /usr/sbin/bluetoothd
syslog    1039  0.0  0.0  30176   896 ?        Sl   May11   0:07 rsyslogd -c5
avahi     1051  0.0  0.0   3560  1436 ?        S    May11   0:01 avahi-daemon: running
avahi     1053  0.0  0.0   3448   220 ?        S    May11   0:00 avahi-daemon: chroot 
root      1056  0.0  0.0      0     0 ?        S<   May11   0:00 [krfcommd]
root      1057  0.0  0.2  25236  5172 ?        Ssl  May11   0:00 NetworkManager
root      1065  0.0  0.1   7784  3072 ?        Ss   May11   0:00 /usr/sbin/cupsd -F
root      1097  0.0  0.1  25500  3624 ?        Sl   May11   0:04 /usr/lib/policykit-1/
colord    1113  0.0  0.1  34480  3892 ?        Sl   May11   0:00 /usr/lib/i386-linux-g
root      1161  0.0  0.0   4632   688 tty4     Ss+  May11   0:00 /sbin/getty -8 38400 
root      1167  0.0  0.0   4632   688 tty5     Ss+  May11   0:00 /sbin/getty -8 38400 
root      1178  0.0  0.0   4632   688 tty2     Ss+  May11   0:00 /sbin/getty -8 38400 
root      1180  0.0  0.0   4632   688 tty3     Ss+  May11   0:00 /sbin/getty -8 38400 
root      1187  0.0  0.0   4632   688 tty6     Ss+  May11   0:00 /sbin/getty -8 38400 
root      1212  0.0  0.0   2176   568 ?        Ss   May11   0:00 acpid -c /etc/acpi/ev
root      1215  0.0  1.5  33092 31108 ?        SLsl May11   0:00 lightdm
whoopsie  1220  0.0  0.1  26212  4056 ?        Ssl  May11   0:00 whoopsie
root      1222  0.0  0.0   2620   824 ?        Ss   May11   0:00 cron
daemon    1223  0.0  0.0   2476    12 ?        Ss   May11   0:00 atd
mysql     1230  0.1  0.1 326696  2276 ?        Ssl  May11   1:28 /usr/sbin/mysqld
root      1303  0.0  0.1  24796  3004 ?        Sl   May11   0:02 /usr/lib/accountsserv
root      1340  0.0  0.0   2372   600 ?        Ss   May11   0:00 /usr/sbin/inetd
root      1384  0.0  0.1  29176  2732 ?        Sl   May11   0:01 /usr/sbin/console-kit
root      1617  0.0  0.1  28656  3380 ?        Sl   May11   0:00 /usr/lib/upower/upowe
root      2024  0.0  0.0   4632   688 tty1     Ss+  May11   0:00 /sbin/getty -8 38400 
rtkit     2079  0.0  0.0  21336  1092 ?        SNl  May11   0:00 /usr/lib/rtkit/rtkit-
root      2264  0.0  0.2  42476  4320 ?        Sl   May11   0:01 /usr/lib/udisks2/udis
thufir    2382  0.0  0.1  51940  3228 ?        Sl   May11   0:06 /usr/lib/gvfs/gvfsd-t
ntp       2444  0.0  0.0   5752  1496 ?        Ss   May11   0:06 /usr/sbin/ntpd -p /va
root      2605  0.0  0.3  17868  6224 ?        S    May11   0:00 /usr/bin/python /usr/
thufir   11069  0.0  0.2 543872  4248 ?        Sl   May11   0:18 /usr/lib/gvfs/gvfsd-t
thufir   12557  8.7  0.0      0     0 ?        Zl   May11 118:10 [firefox] <defunct>
root     12912  0.0  0.0   3196  1032 ?        Ss   May11   0:00 /usr/sbin/dovecot -F 
dovecot  13022  0.0  0.0   2904   664 ?        S    May11   0:00 dovecot/anvil
root     13023  0.0  0.0   3036   824 ?        S    May11   0:00 dovecot/log
root     13025  0.0  0.1   5280  2908 ?        S    May11   0:00 dovecot/config
thufir   13047  0.0 13.1 1125572 266220 ?      S    14:45   0:00 /usr/lib/firefox/fire
brigitte 13471  0.0  0.1  35496  3296 ?        Sl   14:46   0:00 /usr/lib/gvfs/gvfsd-t
thufir   14311  0.0  0.1  43692  3380 ?        Sl   16:07   0:00 /usr/lib/gvfs/gvfsd-t
thufir   14616  0.0  0.2  99612  5528 ?        S<l  16:07   0:02 /usr/bin/pulseaudio -
root     15991  7.3  1.9  70768 39296 tty7     Rs+  16:23  15:01 /usr/bin/X :0 -core -
root     16089  0.0  0.1  16560  3228 ?        Sl   16:23   0:00 lightdm --session-chi
thufir   16221  0.0  0.1  45908  3880 ?        Sl   16:23   0:00 /usr/bin/gnome-keyrin
thufir   16232  0.0  0.0   2232   528 ?        Ss   16:23   0:00 /bin/sh /etc/xdg/xfce
thufir   16265  0.0  0.0   4092   204 ?        Ss   16:23   0:00 /usr/bin/ssh-agent /u
thufir   16268  0.0  0.0   3844   516 ?        S    16:23   0:00 /usr/bin/dbus-launch 
thufir   16269  0.1  0.0   4560  1884 ?        Ss   16:23   0:14 //bin/dbus-daemon --f
thufir   16276  0.0  0.4  33196  9320 ?        Sl   16:23   0:05 xfce4-session
thufir   16278  0.0  0.1   6640  2400 ?        S    16:23   0:00 /usr/lib/i386-linux-g
thufir   16281  0.0  0.6 183172 12832 ?        Sl   16:23   0:12 xfwm4 --display :0.0 
thufir   16283  0.0  0.9 202872 18896 ?        Sl   16:23   0:05 Thunar --sm-client-id
thufir   16286  0.0  0.1  26880  2820 ?        Sl   16:23   0:00 /usr/lib/gvfs/gvfsd
thufir   16290  0.0  0.1  50072  2972 ?        Sl   16:23   0:00 /usr/lib/gvfs//gvfsd-
thufir   16293  0.1  0.7 193400 15732 ?        Sl   16:23   0:23 xfce4-panel --display
thufir   16299  0.0  0.2  53208  4648 ?        Sl   16:23   0:00 /usr/lib/gvfs/gvfs-ud
thufir   16303  0.0  0.3  32428  6328 ?        Ssl  16:23   0:01 xfsettingsd --display
thufir   16304  0.1  0.9 247032 20304 ?        Sl   16:23   0:13 xfdesktop --display :
thufir   16310  0.1  0.3  20788  7280 ?        S    16:23   0:13 /usr/lib/i386-linux-g
thufir   16313  0.0  0.4  31160  8304 ?        Sl   16:23   0:00 /usr/lib/i386-linux-g
thufir   16314  0.6  0.8 272956 16944 ?        Sl   16:23   1:15 gnome-terminal --sm-c
thufir   16316  0.0  0.1  37772  2572 ?        Sl   16:23   0:00 /usr/lib/gvfs/gvfs-af
thufir   16321  0.0  0.1   9456  2864 ?        S    16:23   0:00 /usr/lib/i386-linux-g
thufir   16328  0.0  0.1  27488  2812 ?        Sl   16:23   0:00 /usr/lib/gvfs/gvfs-gp
thufir   16335  0.0  0.4 170976  8436 ?        Sl   16:23   0:00 /usr/lib/i386-linux-g
thufir   16347  0.0  0.1 101216  3388 ?        Sl   16:23   0:00 /usr/lib/gvfs/gvfsd-t
thufir   16351  0.0  0.0   2404   728 ?        S    16:23   0:00 gnome-pty-helper
thufir   16352  0.0  0.2   8152  4632 pts/0    Ss   16:23   0:00 -bash
thufir   16354  0.0  0.2   8144  4500 pts/1    Ss   16:23   0:00 -bash
thufir   16359  0.0  0.2   8144  4580 pts/2    Ss   16:23   0:00 -bash
thufir   16601  0.0  0.5 195944 10424 ?        Sl   16:23   0:01 /usr/lib/gnome-settin
thufir   16606  0.0  0.5  54828 11828 ?        Sl   16:23   0:00 nm-applet
thufir   16612  0.0  0.1   7504  2284 ?        S    16:23   0:02 xscreensaver -no-spla
thufir   16628  0.1  0.8  41724 17080 ?        S    16:23   0:23 /usr/bin/python /usr/
thufir   16636  0.0  0.2  29232  5092 ?        Sl   16:23   0:00 /usr/lib/policykit-1-
thufir   16640  0.0  0.2  52728  4948 ?        Sl   16:23   0:00 zeitgeist-datahub
thufir   16647  0.0  0.3 259944  7960 ?        Ssl  16:23   0:00 xfce4-volumed
thufir   16659  0.0  0.2  42780  4296 ?        Sl   16:24   0:00 /usr/bin/zeitgeist-da
thufir   16676  0.0  0.3  51808  7920 ?        Sl   16:24   0:00 /usr/lib/zeitgeist/ze
thufir   16685  0.0  0.0   4224   280 ?        S    16:24   0:00 /bin/cat
root     16727  0.0  0.0   5944  1844 pts/2    S    16:24   0:00 sudo -s
root     16728  0.0  0.1   6928  3300 pts/2    S+   16:24   0:00 /bin/bash
thufir   16811  0.0  0.1  34376  2856 ?        Sl   16:24   0:00 /usr/lib/at-spi2-core
root     16826  0.0  0.0   5944  1848 pts/1    S    16:24   0:00 sudo -s
root     16827  0.0  0.1   6936  3412 pts/1    S    16:24   0:00 /bin/bash
thufir   17000  0.0  0.2  29564  5644 ?        Sl   16:27   0:00 thunar-volman --devic
root     17742  0.0  0.0      0     0 ?        S    02:00   0:01 [jbd2/sda1-8]
root     17743  0.0  0.0      0     0 ?        S<   02:00   0:00 [ext4-dio-unwrit]
root     18070  0.3  0.0   5200  1428 pts/1    S+   16:39   0:35 top
thufir   18166  7.8  2.1 330548 43576 ?        Sl   16:42  14:31 pidgin
root     18201  0.0  0.0   5944  1848 pts/0    S    16:48   0:00 sudo -s
root     18202  0.0  0.1   6928  3408 pts/0    S    16:48   0:00 /bin/bash
thufir   18326  0.0  0.2   8152  4628 pts/3    Ss   16:54   0:00 -bash
thufir   20249  5.5  4.4 509808 91308 ?        SLl  17:32   7:32 chromium-browser     
thufir   20251  0.0  0.2 111936  5388 ?        S    17:32   0:06 chromium-browser     
thufir   20252  0.0  0.0   2256   316 ?        S    17:32   0:00 /usr/lib/chromium-bro
thufir   20253  0.0  0.5 120596 10440 ?        S    17:32   0:00 chromium-browser --ty
thufir   20257  0.0  0.2 128792  4300 ?        S    17:32   0:00 chromium-browser --ty
thufir   20369  0.0  0.0  10368  1900 ?        S    17:34   0:00 /usr/bin/gnome-keyrin
thufir   20402  0.0  0.2  40448  4068 ?        Sl   17:40   0:00 /usr/lib/gvfs/gvfsd-h
thufir   20438  0.5  0.0      0     0 ?        Z    17:41   0:42 [chromium-browse] <de
root     21258  0.0  0.0   3516   936 ?        S    18:09   0:00 /sbin/udevd --daemon
thufir   21461  0.6  3.4 218276 70976 ?        Sl   18:30   0:29 /usr/lib/chromium-bro
thufir   21504  0.0  0.5 158424 11528 ?        Sl   18:32   0:00 chromium-browser --ty
thufir   21805  0.0  0.1  43272  2820 ?        Sl   18:54   0:00 /usr/lib/gvfs/gvfsd-b
root     21852  0.0  0.0      0     0 ?        S    18:59   0:00 [kworker/0:1]
thufir   21875  0.7  2.0 188328 42504 ?        Sl   19:01   0:19 /usr/lib/chromium-bro
thufir   21959  0.0  0.1  32708  2440 ?        Sl   19:16   0:00 /usr/lib/dconf/dconf-
thufir   22003  0.0  0.1  17180  2372 ?        Sl   19:16   0:00 /usr/lib/gvfs/gvfsd-m
root     23245  0.0  0.0   3516   584 ?        S    19:20   0:00 /sbin/udevd --daemon
thufir   23323  0.2  1.8 180180 38192 ?        Sl   19:23   0:03 /usr/lib/chromium-bro
thufir   23337  1.0  2.2 191596 44820 ?        Sl   19:24   0:15 /usr/lib/chromium-bro
news     23379  0.7  0.7  17720 15864 pts/0    S+   19:39   0:04 fetchnews -vvv
root     23423  0.0  0.0      0     0 ?        S    19:42   0:00 [kworker/0:0]
thufir   23481  5.3  2.0 181672 42408 ?        Sl   19:47   0:04 /usr/lib/chromium-bro
root     23489  0.0  0.0      0     0 ?        S    19:47   0:00 [kworker/0:2]
thufir   23497  0.0  0.0   5204  1164 pts/3    R+   19:48   0:00 ps aux
thufir@dur:~$ 



I cannot start firefox, I get this message:

Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system.