That's not it's only problem. It is, by default, set to "correct" tags from the Internet, and turning it off doesn't work. Many of these "corrections" are actually wrong. While I was still using it, I went to Miscrosoft's own help site and loads of people were reporting the same problem and none of the solutions put forward my Microsoft staff worked.
It also routinely messes up capitalisation, and changes it back to what it wants if you try to change it manually. Useless piece of software.
It's not only tags it has problems with. My old laptop suddenly stopped working unless in safe mode. Basically on startup it froze after being on for about 5 minutes. I decided to to a full reinstall of windows so started manually backing up files so I could. Two of my music files were corrupted. When I researched the issue, WMP re-indexes music files on startup (whether you want it to or not) and it was hanging on the corrupted files. Once I'd deleted those two files the laptop worked fine again.