My macbook runs great until..

Question

so i have a 2.0ghz macbook with 2gb of ram
if i don't have much open it runs like a champ.. super fast.. like just safari and ichat
but if i put in a cd.. and have itunes on (playing from an external hard drive).. and a couple other programs in it slows down big time.. slightly freezing (as in showing the colored wheel and freezing for like 5 or 10 seconds).. and i understand normal slow downs but its not just that.. if i eject the cd or close everything but the small stuff again its still completely messed up.. like only ichat and safari are open again and they continue to freeze and such.. and that goes on until i restart..
i was looking at a system monitoring widget and i can't tell anything really crazy.. processor is less than 70% all that time even when the "big stuff" was open.. and ram was never completely used.. and the temperature.. well the temperature gets hot but its not conistent enough to make me think its the temperature.. it will get really hot but still runs great
also i ran the hardware test from the install cds.. nothing..
could this be hardware related? my 14 days is up tomorrow so im not sure what to do :/
any ideas?

Answer 1

Thank you so much, Mr. Curtis! I'm not sure exactly how that worked, but it allowed me to get back on both AE and Premiere Pro. 10 points to you!
Also, for the  other people that may have similar problems and are viewing this forum, definitely try this out. Listen to Jim's advice, don't use the most recent version (which is currectly 5.5.47) - instead try a slightly older one. The one I had installed was version 5.5.24.
Once again, thank you! You saved my project!