The responsiveness of 2.5.65 is vastly improved over 2.5.64 but there
are some issues still. They appear to be most prominent under 2.5.65 (or
at least that's when the shit hit the fan :) but still happen to some
extent under 2.5.64. Basically this happens under moderate load (I was
compiling mplayer 0.90rc5, had mozilla loaded up and was typing away at
a telnet connection; the system may have been picking up mail at the
time aswell) and the symptoms are:

1. stuttering of mouse and cursor movement
2. eventual loss of keystrokes (as near as I can tell)
3. some major freezeups
4. laptop suddenly powering off. abruptly and totally.

there is nothing in the logs on reboot and a brisk check of dmesg before
the shutdown once produced no clues.

This has been totally reproducable. I got hit by it 5 or so times before
I got the shits with it and went to 2.5.64. Then whilst typing up a bug
report on this and compiling mplayer again, the system suicided once
more. I then fully got the shits with it and went to sleep. :) I've also
had this happen whilst using mozilla. Had about 10 or so pages loading,
I -think- (ie don't give this too much trust) there was a fair bit of
disk activity and then *boom*.

I eventually managed to compile mplayer when I did a nice -n 19 but I'm
not sure if it was due to niceness or if its because I didn't fully
duplicate the previous environment.

Incase it's something to do with disc, hdparm -v output is as follows:

/dev/hda:
 multcount    = 16 (on)
 I/O support  =  1 (32-bit)
 unmaskirq    =  1 (on)
 using_dma    =  1 (on)
 keepsettings =  0 (off)
 nowerr       =  0 (off)
 readonly     =  0 (off)
 readahead    = 256 (on)
 geometry     = 38760/16/63, sectors = 39070080, start = 0
 busstate     =  1 (on)

My .config is attached to the message. If you need more info or for me
to do some mroe experimentation, please holler and I'll see what I can
do. I can't add code to the kernel but I can try and help debug. :)

-- 
"Other countries of course, bear the same risk. But there's no doubt his
hatred is mainly directed at us. After all this is the guy who tried to
kill my dad."
        - George W. Bush Jr, 'President' of Regime of the United States
          September 26, 2002 (from a political fundraiser in Houston, Texas)