Since last patch I finally get quite a lot runtime error messages when starting a mission (game starts normally). It comes when the screen changes to the loading screen.

I initially thought that this was due when I launched COD from the desktop icon (which no longer has a symbol but some default windows icon symbol). But now I also got this runtime error when launching COD from steam. Again at the same location.

However, it does not occur everytime I launch COD.

My OS is Vista 64b

My system:
quad core intel i7 920
6 GB ram
Nvidia GTX 275