The Cato Institute wrote on the subject of UN corruption a few years back:
http://www.cato.org/pubs/pas/pa-253.html
It is much too long to post, but if you are seriously exploring the issue of the UN and whether or not it is worth staying in, you should read it.
After exploring the issue myself, I believe that there is no hope of reforming the UN, mostly because there is no incentive for those who are profiting from it. I say it is time to leave the UN and kick them out of NY...they can use the office space and parking.