Part of the trouble here may be that chrisjj also uses MP3Tag. You have to specify what you want your tags written as in that program, and if you're like me with a select few with foreign characters, you're forced to set that program to write UTF-8. MediaMonkey however has the ability to determine what is needed, so ones without characters out of the norm, it will write in regular ol' ISO, while using UTF for those it needs it on. Thus, if you tag files with MP3Tag and it writes them all as UTF, when you do as suggested in MediaMonkey, it's going to re-write those tags to what is needed (thus converting UTF over to ISO).
I tested on a set of 14 files, since it's the album I had up. It took a couple seconds to run through them, but this album had been written with MP3Tag. Re-doing the same process after, results in the bar going from beginning to end almost instantaneously. May not be the entire problem, but this could suggest while this action seems instantaneous for some of you, while takes a bit for him.
EDIT: Correction, MM uses ACSII (which I believe is the same as saying ISO) and they both use UTF-16 (not
