I've been suffering from these hangups for a while now, only with the recent skype and recent kernels. System specs:

Dell Inspiron 300m
Ubuntu Dapper up-to-date w/ kernel 2.6.15-27-686 (SMP, PREEMPT)
Skype 1.3.0.47_API
List of loaded modules given below

* No VMware is running (ruling out suspect vmware)

* Nothing suspicious in the kernel log (not even "soft lockup"). In fact, I can't find any traces anywhere for such events.

* It happens normally when there is an incoming call (in which case usually the lockup is definite (wel, I've never waited longer than 5 minutes)

* It also happens when there is an incoming chat (in which case usually it freezes for a short while -- around a minute)

* Finally, I've had it happen also when I initiate a call, but that is very rare (lol... both me initiating calls and the freeze upon that).

The bottom line, is that it is so frequent that I've been having to (cold) boot my laptop on average more than 4 times a week... which is close to being intolerable.

Let me know if you need more info, or more testing -- I'll be glad to assist (including trying out debug kernels and so forth).

Oren.

(list of modules:
Module                  Size  Used by
usbhid                 42752  0 
rfcomm                 43604  0 
l2cap                  28192  5 rfcomm
bluetooth              54212  4 rfcomm,l2cap
ipv6                  286976  26 
i915                   21664  1 
drm                    78484  2 i915
ppdev                   9668  0 
speedstep_centrino      8752  1 
cpufreq_userspace       6496  1 
cpufreq_stats           6688  0 
freq_table              4928  2 speedstep_centrino,cpufreq_stats
cpufreq_powersave       1920  0 
cpufreq_ondemand        7752  0 
cpufreq_conservative     9000  0 
video                  16324  0 
tc1100_wmi              6884  0 
sony_acpi               5580  0 
pcc_acpi               12416  0 
hotkey                 11492  0 
dev_acpi               11236  0 
container               4608  0 
button                  6704  0 
acpi_sbs               20172  0 
battery                 9988  1 acpi_sbs
ac                      5220  1 acpi_sbs
i2c_acpi_ec             5120  1 acpi_sbs
i2c_core               22848  1 i2c_acpi_ec
nls_cp437               5888  1 
ntfs                  111728  1 
md_mod                 76052  0 
af_packet              24520  6 
sbp2                   25060  0 
scsi_mod              145960  1 sbp2
parport_pc             37988  0 
lp                     12356  0 
parport                39400  3 ppdev,parport_pc,lp
joydev                 10432  0 
tsdev                   8032  0 
irda                  217980  0 
crc_ccitt               2240  1 irda
snd_intel8x0           35772  3 
snd_ac97_codec        100224  1 snd_intel8x0
snd_ac97_bus            2400  1 snd_ac97_codec
pcmcia                 41948  0 
snd_pcm_oss            56448  0 
snd_mixer_oss          20544  1 snd_pcm_oss
ipw2100                93812  0 
ieee80211              38952  1 ipw2100
ieee80211_crypt         6528  1 ieee80211
snd_pcm                96708  4 snd_intel8x0,snd_ac97_codec,snd_pcm_oss
snd_timer              26884  2 snd_pcm
snd                    60004  10 snd_intel8x0,snd_ac97_codec,snd_pcm_oss,snd_mix
er_oss,snd_pcm,snd_timer
tg3                   113060  0 
yenta_socket           30124  4 
rsrc_nonstatic         14624  1 yenta_socket
pcmcia_core            45272  3 pcmcia,yenta_socket,rsrc_nonstatic
psmouse                40004  0 
serio_raw               7748  0 
shpchp                 49504  0 
pci_hotplug            30788  1 shpchp
soundcore              10784  1 snd
snd_page_alloc         11304  2 snd_intel8x0,snd_pcm
intel_agp              24700  1 
agpgart                36784  3 drm,intel_agp
evdev                  10176  2 
ext3                  148296  3 
jbd                    65876  1 ext3
dm_mod                 63256  5 
ide_generic             1504  0 
ohci1394               37524  0 
ieee1394              306520  2 sbp2,ohci1394
ehci_hcd               36104  0 
uhci_hcd               35536  0 
usbcore               139172  4 usbhid,ehci_hcd,uhci_hcd
ide_disk               19136  4 
piix                   11652  1 
generic                 5124  0 
thermal                13768  0 
processor              26888  2 speedstep_centrino,thermal
fan                     4836  0 
capability              4968  0 
commoncap               7328  1 capability
vga16fb                13992  1 
vgastate               10208  1 vga16fb
fbcon                  43904  72 
tileblit                2784  1 fbcon
font                    8320  1 fbcon
bitblit                 6464  1 fbcon
softcursor              2304  1 bitblit