Cryptovirus variant decryption partly failure with decryption program and key -- 2

A computer got encrypted by a cryptovirus variant. The ransom has been paid, the person received the decrypting program and the keys for it. The only problem is that there are some files that do not get decrypted and the problem seems to be related with speciali latin2 characters in the directoryname. It is weird also that in the same directory we have "[login to view URL]", "[login to view URL]", "[login to view URL]" and a1 and a2 decrypts OK, but a3 doesn't. The person who claims he has the skills to do this will receive a package with some example files, the decrypt program and the keys that caim with it. The project is to decrypt the files that the program wasn't able to for some reason. Payment will only be possible if the 2 example files in question can be successfully decrypted. Otherwise the project is unsuccessful and there is no payment. I will provide original files from backup, encrypted files and of course files after decryption (what the contestant can make by his own too). So just to make things clear. 100% payment when I receive the 2 decrypted files correctly and get an easy method (with a good howto) on how to do that by my own. 0 payment if not. It is very clear. The budget is about 100USD.