Renaming Deletes MP3 Tag Info

[Gardner, Joseph A]

Greetings all. I'm playing around with the rename files function in an effort to standardize my collection of MP3s. Funny thing is, when I rename an MP3, all the Tag info is deleted. Any idea why this would be so when simply retyping a new name for the file doesn't affect the Tag info? Any advice on renaming MP3s and keeping the Tag info intact? I'm running OS X 10.2 and Rev 2.1.

Appreciate!

joe.