ok... I found another thred where a guy suggested it was the memory (it seems that a lot a ppl have had this problem, all runing a Intel chipsæt) so currently i am trying to run memtest86+ on the machine, and if my current memory passes, well then...
I am waiting for some other memory which should arrive tomorrow, or maybe the day after that... Hopefully they will work...
Shuttle SB77G5, Intel Pentium 4 531 (3.0GHz, 1MB L2), Palit Geforce 6600 256MB GDDR3, 200GB Seagate Barracuda SATA, NEC ND 3550 DVD, 2x1GB DDR(I)400
Fedora Core 5, i386