Even more bizarre ... If i draw a circle and do a rebuild with #points, set the points to 10 and delete original curve, the do planar surface it then works .... confused here now.

Latest Nvidia drivers installed, that was fun ... not, played with Diablo 3 for a few minutes and all is fine in there. I am sure I read VC-Red version 2010 causes problems with MoI, so i have removed that, and the solid-works trial i had installed, but it don't fix things ... :(

Martin