That's a strange one Martin, it's quite random, sometimes it works sometimes it doesn't. I did find if inset fails, hit cancel, leave top face selected, hit inset again and it works.
I'm still not finding it 100% reliable (random fails) unless I enter both the Thickness and the Height, in which case my experience is that everything works fine and the tool is perfectly usable. This is with the 2nd version of the Nov 2012 beta - the one with the repaired .sat and .step imports/exports.
Hi Martin, I'm able to reproduce the occasional inconsistent behavior, so there's definitely still some other bug lurking around in there somewhere, sometimes this kind of sporadic failure can be due to bugs using uninitialized memory.
I'll continue to dig into it and see if I can track down this other bug too, it can be hard to get to the bottom of things that don't reproduce reliably though but I'll try.
Hi Martin, so I think I've finally gotten to the bottom of what was going wrong with the Inset case that you posted in this thread - it had to do with a bug in the "test for coincidence between closed curves" mechanism in the geometry library.
I've got it fixed for the next v3 beta and it looks like this case that was behaving with sporadic errors should work properly after that.