Having trouble creating UV grid

I am a Grasshopper newbie and so my problem here might sound really silly, but its been frustrating me for a couple of hours now. Your help will be much appreciated. I have created a simple surface by running a range of values through a graph mapper to create some points. I then created a curve using those points as NURBS control points, copied and moved the surface up in the Z-axis and the lofted the 2 NURBS curves. Now I want to create a UV grid on that surface. So I sent the surface through Divide Domain^2 and then through IsoTrim. It has created the UV grid but it seems that the segments in the V dimension are not congruent, however it works in the other direction. Im so confused. Any suggestions are really appreciated.