iTunes "cannot save library file" error in Vista

I just began ripping my latest pile of cd's into iTunes on my new Vista Media Center PC. Occasionally I get the popup "The iTunes library file cannot be saved. You do not have enough access privileges for thei operation" I checked and double checked the security on all of the iTunes files and folders, and not only do I (the system administrator), but also SYSTEM and Everyone have full access to the folder and files. My library is in C:\Users\Jerry\Music\iTunes\ , which is the default installation directory selected by iTunes. I have almost 11,000 songs, and I have already completely rebuilt the library in this version of iTunes as a means to try to resolve this problem. I am on iTunes 7.2.0.16 , everything on the PC is up to date, and I see nothing that makes this error seem correct. Has anyone else seen this, and do you have a fix? What are the implications of NOT saving the file? Thanks, Jerry