EUREKA! It turns out I was transmitting 4.71 KHz low on 2M this morning. My "Fancy Dan" PLL Lock board isn't working, so my offset compensation is back to the stock factory value i.e. +4.71 KHz. The PLL lock board will have to go back to Elecraft at some point. I may drift around a bit, but at least I'll be in the right place!
KO9A , N5RZ and about 15 others worked on 6M so far. Lots of beacons in too.