Fixed in 4.2.1 now available http://www.jthink.net/jaikoz/jsp/news/start.jsp
The folderseparator mask has been added back in, warning that your mask will be reset even if upgrading from 4.2.0 so you might want to manually make a copy of your mask before upgrading if you have spent any time on it.
Just downloaded this version. The folderseperator is showing up as a double \\ in the example mask in windows. ie, U2\\Boy. Should that be happening?
I will try to apply this mask to some files and see if it affects the actual saving of the music after the mask is applied.
Still shows up correctly in jaikoz outside of preferences as well as appears to save correctly. So not a big deal. By the way, really liking the JS renaming! Been able to do some killer renaming masks which makes the folders look so much cleaner. Awesome Job!!! 