As near as I can tell, the following is related to the last of these incidents:

Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740377] BUG: unable to handle kernel paging request at ff0e0300
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740394] IP: [<c0122c38>] __ticket_spin_lock+0x8/0x20
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740414] *pde = 00000000
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740420] Oops: 0002 [#1] SMP
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740424] last sysfs file: /sys/devices/LNXSYSTM:00/device:00/PNP0C0A:00/power_supply/BAT0/charge_full
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740431] Dumping ftrace buffer:
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740435] (ftrace buffer empty)
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740438] Modules linked in: binfmt_misc radeon ppdev drm bridge stp bnep sbp2 lp parport joydev snd_hda_intel snd_usb_audio snd_pcm_oss snd_mixer_oss snd_seq_dummy snd_pcm snd_usb_lib snd_seq_oss snd_hwdep gspca_zc3xx snd_seq_midi snd_rawmidi gspca_main pcmcia snd_seq_midi_event videodev psmouse snd_seq snd_timer snd_seq_device v4l1_compat serio_raw yenta_socket rsrc_nonstatic wlan_scan_sta pcspkr video pcmcia_core snd soundcore snd_page_alloc i2c_piix4 ath_rate_sample input_polldev output shpchp ati_agp agpgart ath_pci wlan ath_hal(P) usbhid ohci1394 ieee1394 8139too 8139cp mii fbcon tileblit font bitblit softcursor
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740486]
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740491] Pid: 3093, comm: Xorg Tainted: P (2.6.28-17-generic #58-Ubuntu) Satellite A100
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740495] EIP: 0060:[<c0122c38>] EFLAGS: 00013092 CPU: 0
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740498] EIP is at __ticket_spin_lock+0x8/0x20
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740501] EAX: ff0e0300 EBX: f6351c90 ECX: 00000005 EDX: 00000100
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740504] ESI: 00003292 EDI: 00000000 EBP: f6351b0c ESP: f6351b0c
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740506] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740509] Process Xorg (pid: 3093, ti=f6350000 task=f63725b0 task.ti=f6350000)
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740512] Stack:
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740514] f6351b14 c0122d58 f6351b24 c05003ee f6351c90 ff0e0300 f6351b34 c014f159
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740521] f3fce700 f6351bf0 f6351b50 c01cc4e4 ff0e0300 f3fc9300 f3fce700 f6351bf0
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740527] f3fc9300 f6351b60 c04999f7 c053f0a0 00001000 f6351b6c c04220ef 0000000c
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740534] Call Trace:
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740537] [<c0122d58>] ? default_spin_lock_flags+0x8/0x10
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740542] [<c05003ee>] ? _spin_lock_irqsave+0x2e/0x40
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740549] [<c014f159>] ? add_wait_queue+0x19/0x50
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740557] [<c01cc4e4>] ? __pollwait+0x64/0xe0
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740565] [<c04999f7>] ? unix_poll+0x17/0xb0
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740572] [<c04220ef>] ? sock_poll+0xf/0x20
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740579] [<c01cc16e>] ? do_select+0x2fe/0x610
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740584] [<c01cc480>] ? __pollwait+0x0/0xe0
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740587] [<c0133de0>] ? default_wake_function+0x0/0x10
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740592] [<c0133de0>] ? default_wake_function+0x0/0x10
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740595] [<c0133de0>] ? default_wake_function+0x0/0x10
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740599] [<c0133de0>] ? default_wake_function+0x0/0x10
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740602] [<c0133de0>] ? default_wake_function+0x0/0x10
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740606] [<c0133de0>] ? default_wake_function+0x0/0x10
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740609] [<c0132248>] ? enqueue_task_fair+0x68/0x70
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740612] [<c0131cde>] ? resched_task+0x1e/0x70
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740616] [<c0133c54>] ? try_to_wake_up+0x104/0x290
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740619] [<c0133deb>] ? default_wake_function+0xb/0x10
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740623] [<c0128ec0>] ? __wake_up_common+0x40/0x70
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740628] [<c015846d>] ? clocksource_get_next+0x3d/0x50
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740636] [<c0157092>] ? update_wall_time+0x4c2/0x8e0
Dec 10 18:16:49 stoke-buntu kernel: [ 3063.740639] [<c0156ad3>] ? getnstimeofday+0x53/0x110
Dec 10 18:16:50 stoke-buntu kernel: [ 3063.740643] [<c04285fd>] ? skb_dequeue+0x4d/0x70
Dec 10 18:16:50 stoke-buntu kernel: [ 3063.740649] [<c049cb47>] ? unix_stream_recvmsg+0x227/0x490
Dec 10 18:16:50 stoke-buntu kernel: [ 3063.740653] [<c0127c05>] ? sched_slice+0x35/0x50
Dec 10 18:16:50 stoke-buntu kernel: [ 3063.740657] [<c02a8e70>] ? apparmor_socket_recvmsg+0x10/0x20
Dec 10 18:16:50 stoke-buntu kernel: [ 3063.740667] [<c01cc6a4>] ? core_sys_select+0x144/0x270
Dec 10 18:16:50 stoke-buntu kernel: [ 3063.740671] [<c0152b5a>] ? hrtimer_try_to_cancel+0x3a/0x90
Dec 10 18:16:50 stoke-buntu kernel: [ 3063.740675] [<c0156ad3>] ? getnstimeofday+0x53/0x110
Dec 10 18:16:50 stoke-buntu kernel: [ 3063.740679] [<c01cc9ac>] ? sys_select+0x2c/0xb0
Dec 10 18:16:50 stoke-buntu kernel: [ 3063.740683] [<c0103f6b>] ? sysenter_do_call+0x12/0x2f
Dec 10 18:16:50 stoke-buntu kernel: [ 3063.740687] Code: ff ff 90 b9 0a 2b 12 c0 b8 0d 2b 12 c0 e9 59 ff ff ff 90 b9 10 2b 12 c0 b8 13 2b 12 c0 e9 49 ff ff ff 90 55 ba 00 01 00 00 89 e5 <3e> 66 0f c1 10 38 f2 74 06 f3 90 8a 10 eb f6 5d c3 8d b4 26 00
Dec 10 18:16:50 stoke-buntu kernel: [ 3063.740723] EIP: [<c0122c38>] __ticket_spin_lock+0x8/0x20 SS:ESP 0068:f6351b0c
Dec 10 18:16:50 stoke-buntu kernel: [ 3063.740731] ---[ end trace baf45a2c3dde8172 ]---
Dec 10 18:16:50 stoke-buntu gdm[3089]: WARNING: gdm_slave_xioerror_handler: Fatal X error - Restarting :0
Dec 10 18:16:50 stoke-buntu NetworkManager: <info> (ath0): device state change: 8 -> 3
Dec 10 18:16:50 stoke-buntu kernel: [ 3063.756220] [drm] Num pipes: 2
Dec 10 18:16:50 stoke-buntu NetworkManager: <info> (ath0): deactivating device (reason: 3.
Dec 10 18:16:50 stoke-buntu NetworkManager: <info> ath0: canceled DHCP transaction, dhcp client pid 3829
Dec 10 18:16:50 stoke-buntu NetworkManager: <WARN> check_one_route(): (ath0) error -34 returned from rtnl_route_del(): Sucess
Dec 10 18:16:50 stoke-buntu avahi-daemon[3164]: Withdrawing address record for 192.168.1.100 on ath0.
Dec 10 18:16:50 stoke-buntu avahi-daemon[3164]: Leaving mDNS multicast group on interface ath0.IPv4 with address 192.168.1.100.
Dec 10 18:16:50 stoke-buntu avahi-daemon[3164]: Interface ath0.IPv4 no longer relevant for mDNS.
Dec 10 18:16:55 stoke-buntu bonobo-activation-server (ian-6237): could not associate with desktop session: Failed to connect to socket /tmp/dbus-IH4befunJ7: Connection refused
Dec 10 18:16:57 stoke-buntu gdm[3086]: CRITICAL: gdm_config_value_get_bool: assertion `value->type == GDM_CONFIG_VALUE_BOOL' failed
Dec 10 18:17:01 stoke-buntu /USR/SBIN/CRON[6313]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Dec 10 18:17:04 stoke-buntu gdm[3086]: WARNING: Failed to start X server several times in a short time period; disabling display :0
Dec 10 18:17:13 stoke-buntu ntpd[4043]: Deleting interface #5 ath0, 192.168.1.100#123, interface stats: received=35, sent=35, dropped=0, active_time=3001 secs
Dec 10 18:18:38 stoke-buntu init: tty4 main process (2272) killed by TERM signal
Dec 10 18:18:38 stoke-buntu init: tty5 main process (2273) killed by TERM signal
Dec 10 18:18:38 stoke-buntu init: tty2 main process (2279) killed by TERM signal
Dec 10 18:18:38 stoke-buntu init: tty3 main process (2282) killed by TERM signal
Dec 10 18:18:38 stoke-buntu init: tty6 main process (2283) killed by TERM signal
Dec 10 18:18:38 stoke-buntu init: tty1 main process (3430) killed by TERM signal
Dec 10 18:18:39 stoke-buntu init: control-alt-delete respawning too fast, stopped
Dec 10 18:18:39 stoke-buntu last message repeated 8 times
Dec 10 18:18:45 stoke-buntu bluetoothd[3052]: bridge pan0 removed
Dec 10 18:18:45 stoke-buntu bluetoothd[3052]: Stopping SDP server
Dec 10 18:18:45 stoke-buntu bluetoothd[3052]: Exit
Dec 10 18:18:45 stoke-buntu exiting on signal 15
Dec 10 18:19:29 stoke-buntu syslogd 1.5.0#5ubuntu3: restart.