MP3Tag vs FB2K Tags

Can anyone solve this for me?
MP3Tag works great everywhere. FB2K reads the tags fine. BUT, when you edit in FB2K, the changes fails to display correctly in MP3T.
For example, we use ';' as the de-limiter in the genre tag (eg: Rock; Cover'. This is fine, and FB2K reads them OK. However, when you edit that field in FB2K (it's just easier and quicker to do that sometimes!), then when the file is opened in MP3T, the ';' has become '\' (eg: Rock\Cover'). This causes only the first tag to show in MP3T's Genre column (although the multiple tags do show in the Tag Panel when the song is selected). Hope all that makes sense?!!

Both programs can deal with multi-value fields.
MP3tag shows the separator as \\.
FB2k shows the separator as ;.
If you want to see multi-value fields in a column, you have to enter as
Value: $meta_sep(genre,\\)