Thanks Florian for adding WAV support, but...
I find that a WAV file with a tag field created with GoldWave and having non-ASCII character displays fine in Windows 7 Explorer, but in Mp3tag displays truncated e.g.
It displays fine in dBpowerAmp too http://i.imgur.com/85KgTno.png .
Such a tag created in Mp3tag works fine, but presumably that's because Mp3tag is storing in a different format - INAM + ID3.
Here's the binary:
This isn't just display. Export shows the corruption. I'd guess all Mp3tag operations suffer.
This failure doesn't happen when the format is WMA and MP3.