Linux Dropped frames, black screen

Hey all.

I'm currently running XBMC on top of Ubuntu Desktop 12.10.
I have been experiencing some strange things lately. Firstly is the video lag. While watching 720p/1080p content (not full bitrate rips) it will drop frames, lose sync, and buffer. I fixed the buffer by using a gigabit ethernet connection instead, though the frames are still being dropped. I'm not sure what is going on. I'm running a dedicated HTPC with an i3 530 with 2GB RAM. I don't have a dedicated GPU though, so the onboard GPU is taking care of that.

Secondly, on occasion, the screen will go black, for roughly 3 seconds. Everything disappears, sound and video. It will then come back on again after this time?

I will try and attach a pastebin file later.

Has anyone else had these problems?

debug log

A guess would be video drivers need to be updated or you are using generic drivers and need non-generic.