Oh, so there is a correlation! Just to be sure, could you check if the folder game you copied has those files? (just want to make sure it's not a problem with makeps3iso or iso mounting). If possible (if they are in the folder game you're using), try deleting them, delete the game data, and boot up the game. Does it fail?*edit* Seems like its windows is causing these Thumb.db files to go missing when building iso on pc, which then causes the game data install to fail.
Now I wonder (assuming the ISO isn't the problem), were those Thumbs.db repurposed for the game, or is it a copy protection? If they are the same as the Thumbs.db files from windows, you might be able to extract the image they contain (though, of you're using a Windows machine, you might need to check the md5sum of the file to make sure it isn't overwritten). There is a tutorial online on how to show them in file manager (though, show hidden files might do the trick).