Computer Freezes when an Explosion is near the player

Hello There

On two occasions, My computer has froze and locked up when a massive explosion is right near the player. The first was the Nitroglycerine Swep. I destroyed it while standing quite close. The second time i had the Timed Bomb Swep (where you set the time and it explodes after the timer hits zero) and it froze the computer when it exploded as well. No blue screen or anything. The computer has just been fitted with a new motherboard by a computer shop so it can’t be the Mobo. I used to have a memory leak, but that has been fixed as well. But this freezing only happens in Gmod and only when an explosion is right near my player. Just seems really bizarre to me O_O. Any help would greatly be appreciated.

Thanks in Advance

It sounds like your video adapter cant handle the graphics of the explosions. At least that is what my issue is.

I doubt it is that. I have a GeForce GTX 280. But i did install a new Mobo recently. Maybe there is something conflicting? It has a build in VGA adaptor so maybe that is attempting to enable itself as well as the 280?

Just a quick update, I installed Service Pack 2 On Vista Lately and Have not Updated my DirectX and Nvidia drivers. I read somewhere that you need to do this, Are those sources correct?