fc3 randomly freezing on a Dell Inspiron 5150

[Peter James Morgan]

Hi,

I have a Dell Inspiron 5150 laptop that has been running FC1 for the 
last year (or so). I took the plunge last weekend and did a clean 
install on the machine with FC3. Very impressed by the smooth 
installation, and initially very happy - especially with "yum update" 
very neat!

However, the machine is now "freezing" on a semi random basis, 
particularly under heavy load. Though, I left it alone idling today and 
when I came back it had again frozen. When it freezes under load, the 
CPU fan can be heard at (I guess) 100% for a couple of minutes while it 
is frozen, then shortly after the machine powers itself off. The last 
couple of under load freeze were at the same time as the CPU fan 
stepping up another "gear".

The freeze happens when running under 2.6.10-1.760_FC3smp (the machine 
is HT with a 3Ghz Intel processor) and also 2.6.10-1.760_FC3.

With acpi=off, the machine appears to be stable.

With FC1 I was able to run this laptop with acpi=on (only with 
uniprocessor mode, didn't trust HT with 2.4), without any problems with 
stability.

Unfortunately, nothing of interest is being written to /var/log. Is 
there a recommended mechanism of debugging this fault? Any pointers to 
other things that I can configure (e.g., could the CPU speed stepping be 
the source of the problem?)

Thanks,
Peter.