sudden freeze

[Jenei Gábor <jen.gab@gmail.com>]

Hello,

I've been using Debian quite long, but recently I have a strange 
problem. On my MSI Wind U123 netbook I have the following problem: 
system boots, it works for about 5-30 minutes, then suddenly it escapes 
to shell(like when I push ctrl+alt+F1) and the mouse coursor stays in 
this shell prompt also(the original gnome mouse cursor) After this I 
cannot do anything, the system doesn't react. Do you know my problem? Or 
could I debug it form system logs? I guess the problem's source must be 
somewhere in energy handling, as the problem never appeared me before 
when I was using the netbook from electrical network, only in case of 
running from battery. Actually I only can reboot the system by pressing 
the power button long.

Thanks for your help,

Gabor Jenei