Well, I'm sad to report, that the good behavior didn't last. I don't know if I mentioned it or not, but after it starts the stuttering with any media, it soon becomes too slow to use and a "shutter-like effect" takes place where the screen changes tint from top to bottom several times and finally a message in many languages pops up that says something to the effect of your computer must shut down now and quickly disappears under the shade effect and then the user must hold down the power key to shut it down. My wife is the sole user of the computer and says that this all started with the last major Safari update. Applecare advised if we buy and install Snow Leopard it would behave. While that proved true for a couple weeks, it returned. I've reset the PRAM and SMC to no avail. I have a feeling this is hardware related, but everything tests good.... Very frustrating. The battery issue is a separate issue, I believe.