problem with loop

problem is, that grasshopper doesn't really stop drawing these components at the end of the uv-surface. that's what's coloured red, there gh draws about 550 surfaces, or about 65 components in one field...

the switch works, the only thing i did, was to add a second slider to the divide component, so now there are two slider, one for the u, one for the v. that works great, but just with odd numbers of division (right.tif). with even numbers it comes out like you can see in wrong.tif ...

so does anyone know how to fix that even/odd thing? and am i right to think, that the loop-thing has to do with a missing list length component?

thanks a lot, a nice weekend to everyone, p