Hi Florian,
Just a little suggestion:
now if I edit a field in the Tag Panel, and I switch to another window (e.g. the web browser, or the image viewer) to see the data I need to put in that edited field, after returning to MP3Tag the content of the field will be auto-selected, so I cannot continue the typing, I have to push the End button for example, or click the original position of the cursor.
Yes, it is not a big job, but I use the program a lot, and this thing is not very comfortable.
Sorry for my big problems. 
st