Had a look at kern.log after reading earlier post found:
Nov 22 22:20:01 sibs-laptop kernel: [2.176614] Marking TSC unstable due to
TSC halts in idle
Nov 22 22:20:01 sibs-laptop kernel: [2.176637] ACPI: CPU0
Since installing Karmic my fan has been operating at high speed too
often for my liking and now I've had a number of unexpected shutdowns
whilst using Firefox or transcoding using dvd::rip, particularly when
doing both . I got the following errors from the last shutdown after it
hung:
Modem Manage
