Intermittent crash early in boot up - kernel oops?

[Morgan Collett]

I have a strange, intermittent kernel oops crash when booting up Ubuntu. 
It usually happens when I reboot from WinXP to Ubuntu, although I 
haven't done it often enough to verify that. If I power off and on 
again, then it boots up fine.

Screen shots of the kernel messages are here:
http://www.mcode.co.za/graphics/ubuntu/boot1.jpg
http://www.mcode.co.za/graphics/ubuntu/boot2.jpg

Hardware: Sony VAIO PCG-FX190 laptop, 512MB RAM, PIII 850.

Any ideas?

Morgan