Hello redlion. You're fine. That is Windows' default Reason Phrase for a 301. It is the Status Code that is important, the Reason Phrase can be whatever although the official phrase is Moved Permanently
That bugged me for the longest time (when we were using IIS for 301s) because I wanted to be in line with the specification. I've since switched to ISAPI_Rewrite and use the facilities in that program to handle all 301s.