cd recording problem

[nongv]

when i record my cd my mouse moves kinda of jittery like it jumps. it seems like i am running alot of program. last time i was recording it wasn't like that. my cd recorder has buffer under run and last time i was recording i could surf the net with out waiting like 3 minutes for it to load. i also get error out when i am recording cd and i get a bad burn. it has buffer under run so why am i getting this. the last thing i did was put in a hard drive to copy stuff over to it and take it out. after i did that i started to get all this problem.