I have noticed that directories have been created in my ~/Documents area with % in names (eg "My%Directory"). They are usually based on the name of another directory (eg. "My Directory") in Doc's but with the spaces in these directories replaced by %'s.
These directories are empty except for one subdirectory in each which is another replica of a subdirectory name under "My Directory" (eg. "My%Directory/Another" from "My Directory/Another"). This subdirectory is empty except for a 0 bit *.mm file.
I have noticed it only happens in directories of the original "My Directory" in which I had a subdirectory with a Freemind *.mm (mind maps) file. I assume it may be related to Freemind, or is this a OS issue?