This might be getting me a little closer to a solution. I'm noticing a large amount of space deep within one of the service account's user settings, but it's not letting me get in there very easily. So, assuming I can get Windows to give me access to this folder, I can probably figure out what files are in there. Seems to be an issue with the INetCache folder in several users' accounts. Thanks for pointing me this direction. I'll update when I figure something out.
