Lost Flac Songs On Art Tagging

Here is problem that is getting worce.
When go to tag Flac files I random lose a song in album,
Can change text just seems to happen when adding art.
The flac file plays in foobar before tagging.
If I redo transfer of deleated song it tags art fine seems random.

Should I reinstall MP3Tag ?

Any help be great !

I still have this problem , I did remove & reinstall , it seemed to fix at first.

Using Windows XP.

Only seems to happen when adding art.

Any Ideas ?

I still have not found solution , any ideas at all ?

For any help .