It is possibly a problem with the Win7 virtualstore garbage.
Microsoft in its minute wisdom decided programs are not allowed to write files in the "Program Files" directory structure. Something which many programs do. To avoid breaking so many programs the OS silently places such writes in another location called the virtualstore.
Win7 also tries to fool the programs by making things in virtualstore look like they are in "Program files". I can't remember if it tries to fool users in explorer the same way (I never managed to stand UAC which this shit is part of for more than a couple of days). Sometimes or with some programs it fails to fool them and the program can't see a file it has just written.
The short version is don't create your libraries in the "Program files" directory tree and don't try modifying the ones that are already there (if you can actually tell where they are anyway - lol).