======= Date Modified 24 Nov 2010 04:11:15 =======
Hi, I don't see any problem with that. Have you tried to publish your negative results? There is a new open access journals that is accepting negative results and I think is very interesting. This is the link for The All Results Journals:

http://www.arjournals.com/ojs/index.php?journal=Biol&page=index

I think if you have something published it will be much easier to defend your thesis. Do not give up, as they said in their website: "All your results are good results!! (cool slogan, right?)