It is very hard to be able to fix Worldedit, granted that Dakota likely has to focus on much larger bugs that we haven't quite noticed, and dupe glitches continue to pop up server-wide that he has to patch immediately before it becomes too big of a bug.
I understand your frustration, as I myself have purchased worldedit as well, but keep in mind that Dakota has to focus on not only maintaining several different servers and making sure that the resets don't become so ridiculously out of hand, but he is also working on fixing many other large bugs as well.
I'm sure worldedit will be fixed in due time, but if players would stop duping objects with worldedit, that'd be much easier and worldedit wouldn't be as blocked off as it is now. Sigh. I guess that's just why we can't have nice things.