Problems with Getaway & Manhunt

[Prof_F]

Update:

tried the games on my friend's PS2. Manhunt ran the same with audio stuttering during "executions" as it did on my PS2. Getaway ran a little better but not as good as his own backup (on a 4x Ricoh dvd+r).

Bought the cleanerset today ( a disc with "6 ultra fine cleaning brushes", ahem...). Getaway seems to be running a little better now. Still problems at the titlescreen, but it loads alright and there are no problems with cutscenes and audio. Haven't had the chance to test Manhunt.

Could it also be that I made the Manhunt-image with Nero?

ps. is it wise to burn @ 4x or should I stick to 2x?