I don't know if this has anything to do with #367, but I personally have a problem with the same topic.
Comparing two 7z files with password without encrypted file names works fine, it asks for the password and that's it.
But, with two 7z files with password and encrypted file names, I get an error saying "System can't access the file".
It could have something to do with my OS, since I had some trouble with it recently, but I preferred to ask here first, before investigate further for nothing.