Hi,
first thank you for maintaining MP3Tag, because it's the best freeware to do this 
I have a bug since few years, so I contact you.
I work with a NAS (Synology), so I treat my files over a sharing directory \\mynas\sharing\directory*.mp3
The writing of files failed randomly. How to reproduice :
1- Open a smb/cifs sharing \\mynas\sharing\directory\ (you can map as network connector on Z: if you want, the issue will be the same)
2- Select *.mp3 files, right clic > open with > MP3Tag
3- Select all mp3 files with ctrl+a
4- Right click on cover > delete
5- Save with CTRL-S : BUG ! 

If I save again the issue appear randomly on other files (3/10 failed for example)
If I copy all mp3 files on my local HDD, no issue.
Do you know why ?
Thank you !
