patching hardships
 

im trying to model this 360 modena going by the mclearan tut, but im having some problems:

i understand you need 4 splines in order to patch a surface, but sometimes i have 4 splines but it wont let me patch, it says the curves do not match and that sort of thing.

what could i be doing wrong. what are the criteria for making a patch from 4 splines?

can you please explain what im doing wrong? i just need to get this figured out and i should be able to pretty much finish the model.
this is my spline map so far:
http://www.firedragon.com/~lwg3d/upl...1-50901_tn.jpg


also, when i try to shift Z some points, this is an example of what happens:

http://www.firedragon.com/~lwg3d/upl...1-51061_tn.jpg

Make sure that where the curves cross that the points are welded. Otherwise you end up with an open surface for Lightwave to try and patch.