Did anybody else see the mesh faces flash red when you were pulling or pushing vertices?
It used to happen on my system during the early builds about a year ago, it was like a warning that you were doing something wrong.

This has not been present for about 3 builds now, just wondering if I was drinking too much back then!

Thanks for confirming I was not hallucinating Tim, I actually thought it was built in as a warning, then I thought there was not much point as I ignored the warnings and carried on pushing and pulling!