Interesting....
Do you get any LUA errors?
If you don't know what a LUA error is download a couple of addons called Bugsack and bug grabber.
http://www.curse.com/addons/wow/bugsack
http://www.curse.com/addons/wow/bug-grabber
With them two addons installed you will have a little sack on your carb app bar. When it is green you have no bugs.. Red means you have caught a bug! You then need to copy and paste it here.
These lua error reports greatly help in identifying what went wrong...