Hi, I have an Asus K42Jc notebook that runs fine with Windows without any problem, the hang is such that no sysrq combination works. There's no log messages logged, at the time of freezing(before). And I can only recover the machine by restarting by power switch. Here's a list of distros and their statuses,

Distro, BIOS version, Stability
----------------------------
Ubuntu Natty, v214, Stable until a kernel update happened(security feature)
Ubuntu Oneric, v215(updated because new nvidia windows driver got frozen with the BIOS), Not stable, random freezes(as described above)
Fedora 15, v215, Not stable, froze at first boot after installation and the froze while I was using it.

Kernel versions tested: 2.6.38-8 to 3.0.0-12(oneric, got frozen on this one too)
I really dont know where to report this as a bug since there's nothing on the logs and i cant reproduce the freezing, any help is appreciated.