Test-compiling often would be a good idea for your next maps... in that way you'll spot errors much faster and you can fix them on the go. I remember an article that stated you should never leave errors to be fixed later, as you'll forget about them or they become so annyoing/complex that it's nearly impossible to do.
As for your map... this error can also occur with texture axis perpendicular to their faces. Have you checked for problems in Hammer yet?