Kmenu is working a little strange with me. I up graded from 3.5 to 4.2 with no major difficulties. What I noticed though is that when I go into kmenu editor, almost every entry as a dupticate. The strange thing though is that if I do a cut and paste, a) the cut does not delete the entry and b) the paste doesn't always show up on kmenu on the first save attempt every time, second or third provided a change to the entry was made however small. The major question I have for this though is, is there anyway of getting rid of the duplicates easily, or will I have to delete them one at a time?

First, check for any edited entries in $(kde4-config --localprefix)/share/applnk/ and move them somewhere else. This will revert any changes.
Then try running "kbuildsycoca4 --noincremental" which will flush any old entries from the system.

That didn't do anything for me. So I decided to do it manually by hitting the del button. I then am trying to save it and all it is doing is running updating over and over for hours and not updating anything. I believe related to this is kmenu editor finds things and the update doesn't work either. Is this a bug, a bad install, a bad configuration, or what?

As an experiment I installed kmenu (which was for kde 3.5). this uninstalled 5 or so apps. I reinstalled them and loe and behold kmenu for kde 4.2 now work like it supposed to, no dups can move things around and save in less then a second. There must have been a bad install at one point, and therefore things didn't work well at all.

Kmenu Editor worked once or twice, now it is trying something new. It will save, but arrange things in the order it wants it. There is a definite bug in kmenu edit if it cannot save properly or not at all. I will wait until future upgrades before I try again.

If a bug does not already exist for the behaviour you describe at bugs.kde.org, please file one.