Older PC, new problems.

[Bop]

Alright I have a secondary PC for when my friends come over so we can play HL mods and Q3 engine games but a new problem has arrisen from thin air. Actually it happened once in awhile when it was my main PC, but only when OCed to high levels.

Well anyways my problem is when I play a Q3 engine game it will hardlock with the most annoying repeating/squealing from my speakers. This happens in HL sometimes too. Here are my system specs:

Pentium 4 1.7ghz @ stock speeds, antec HSF
ASUS P4T, latest BIOS
640MB 800mhz RDRAM
GeForce 3 Ti500, tried 40 series drivers and 50 series
Sound Blaster Audigy 2, latest updates(sharing an IRQ, will try to change PCI slots)
Kenwood 52x CD-ROM

 

[Hyper_Psycho]

could it be that your card is maybe overheating ? do you have a good airflow through this case ?
is the fan (if there is one) mounted properly ?