That's all very very strange. I wonder if there is something in the firmware that is causing it! That will prompt me to do a new printout of the current firmware and contemplate it during my train ride to/from work...
I have exactly the same experience Paul. I am gradually zeroing in on the perfect clock setting and am currently at?19984500 for the entry of the System Clock. This has kept it pretty close to the BBC time signal for 24 hours. Funnily enough, when I listen in on my FT 857 D, the clock can clearly be taken to zero beat in USB ?mode at 20,002,000. Very odd, but I have mine keeping time quite well now. If I set SYSTEM CLOCK to the value of the actual clock oscillation the clock runs slow.
