Comment 9 for bug 66500

ACPI problem can be worked around by also using no_timer_check. I have checked newer kernels (2.6.18 and 2.6.19-rc6) and none of those seems to be affected. I'd recommend either back-porting the relevant patch or adding "notsc no_timer_check" to the default boot options (is that possible?). From my understanding of the problem (all posts I found on the net). All Dell laptops with a Core 2 Duo CPU are affected and it seems likely that this extends beyond Dell. The problem happens only with the AMD64 version, not the i386 version.
Relevant posts (without which I wouldn't be able to run Edgy):
http://ubuntuforums.org/showthread.php?t=285683
http://ubuntuforums.org/showthread.php?s=bc6fa3c48c258f8d29afa7d90d7d8acc&t=296354
http://doc.gwos.org/index.php/Double_Clock_Speed
I think there should be enough info in those posts to confirm that the bug is real and affects lots of people.