forgot to mention that deleting history does not solve this problem...help please...
Solve what problem???
Hmm if you have trims on the surface it wouldnt work, also if you had differenet parametrisation on them is might cause miss beahivour.
NURBS = Not Understud Realy By Some? 
(Non Uniform B Spline) or perhaps Never Used Right Before Showed...
how about
Now U Really Be Screwed
Joojaa (Rational!)
maybe Became would be better... 
Now the real thing with nurbs is that you need to understand how they work and you need to pay special atention on what you cant do (and what you shouldnt).
The man problem is that while nurbs are great its not the way most people think about objects in realworld (unless you happen to build things out of plastic or metallic plates then it all makes sense, execept tesselation offcourse). I have this eternity project going on where I try to explain this (mainly because im sick an tired of repeating myself), its just that i would need to finish some pictures and read it thru fix some problems etc...
Also if may would incorporate a few changes then it could be far more intuitive to do this.