File renaming problems

Any idea why I'm getting this error? I'm trying to correct the case of the file and I get this. I get this on a couple of files actually, but I'm not sure why. Notice the capital b in the renamed file. It just doesn't like it. I can rename the file to something else and then to the correct case, but not in the first place. Any ideas?

[root@closetlinux CSI]# mv "CSI - 02x06 - Alter boys.avi" "CSI - 02x06 - Alter Boys.avi"
mv: `CSI - 02x06 - Alter boys.avi' and `CSI - 02x06 - Alter boys.avi' are the same file