yes, it is My program doesn't recognize uploading files with Unicode name it is quite difficult to implement all different languages, then change letters to unicode ... some servers don't support it, so I would have to control this as well ...
the only solution for now is using only A-Z,a-z,0-9 (repack it in winrar)
BTW. I never expected that this program will be so widely used, so I didn't think of this