I have got this problem with my PS3 where the audio stutters, video skips and video/audio and gameplay freezes radomly on some games, namely God of War 3 and Uncharted 2. In God Of War 3 the audio stutters and loops frequently like when a character grunts it happens for the like 15 minutes only to have another problem, different stuttering and looping sound happen at the same time. Also the video at times doesn't appear and there is just audio and subtitles, the video then appears but with no audio. This also applies to gameplay. Also the there are problems like extreme ghosting and in rare cases random thick read lines popping out of no where.
Its like this but worse:
To attempt to fix the problem I replaced my hard drive as well as rbuild my database and restore my system but this problem still exists.
I also no longer have my warranty as I have had my PS3 for almost 2 and a half years.