strange signs in ID3 based renamings

[balaweef]

With some MP3 files i have strange signs that appear.
I used the setting 4 to delete the complete filename, and then option 5 to put the prefix %t (title of ID3 tag)
Then I get
This Time I'm Doin It for Love桔獩吠浩⁥❉潄湩䤠⁴潦⁲潌敶
instead of
This Time I'm Doin it For Love

another example
I get
Adagio Adagio Voor Strijkers &摁条潩䄠慤楧潖牯匠牴橩敫獲☠ni
when i should get
Adagio Adagio Voor Strijkers & Clavecimbel in G Klein_Gn - Tommaso Albinoni
(notice that the 2 last letters "ni" are retained.

I have the impression I only get this with long titles
Looking into the ID3v1 and ID3v2 data i don't see those strange signs. I used sevral MP3 viewers/editors. I even rewrote the complete content, I also checked the MP3 file with notepoad++ and nowhere the strrange signs were shown. Using Mediamonkey for renaming does not show those strange signs.
Unfortunately i can't attach the file for you to check. If needed let me know how

Is this a bug? Or am i doing something wrong. Or do you have a solution