Comment 5 for bug 446274

I have installed Karmic beta and had the first freeze today. Laptop was just sitting idle, don't know for how long exactly.
Screen was black and no way to wake the laptop up again but to do a hard reboot (turn off-on).

One clue may be that the boot process complains of an unknown BIOS version: Acer Aspire 5100 v1.80...

Will keep testing, but it seems the issue is still there.