Hi both.
While I'm aware the curve shouldn't be used as trim object, I didn't know distance to 0 was an issue in that range.
I'm used to having issues like that in Softimage, but because Rhino worked, I just assumed Moi would too!
I did try boolean as well, but it din't work for same reasons. Moving to 0 all is good now, thank you :)

M

<< the curve shouldn't be used as trim object
if you select both triming objet(s) + it's curves = problem but alone no problem !

In normal way Curve(s) can also be used as "cutting knife" solid! ;)