I'm having a bit of a problem with half-life 2 and looping sounds. I'll start with my specs and move on to the problem itself.

Athlon XP 2600
ABit KD7-G mobo
Gainward Geforce 6800le 128mb
1024mb DDR400
SB Audigy
+some other bits and bobs
Note: all drivers are up-to-date and windows is fully patched.

When I first got the game, everything ran swimmingly, then I downloaded Lost Coast and a couple of mods and, bang, a problem (yes I have tried it without these mods present).

Here's the issue. I run the game, or any number of mods, and the game will run ok initially, perhaps for 10 seconds, perhaps for 30 minutes, and then all of a sudden the screen will go into standby and the sound will loop. The only way out is a push of the reset button.

A little searching about and I found this Steam Support post . I've followed the advice given and haven't had any success. Things like turning off sound, changing the DX level, updating drivers, window mode, etc. I've tried uninstalling/reinstalling HL2 and I've done a format recently so the PC is running nicely. I'd hoped that was the issue gone but alas it seems valve have made a balls up in updating steam. It seems I'm not alone in this problem however as there are hundreds of posts on numerous forums about this problem.

Does anyone have any ideas on how to fix this? Has anyone been experiencing the same thing?