Thanks for the suggestion - I did just manage to fix it though - tried all of the USB ports, out of 8, finally got one to see the keyboard!
Why 6, you ask? Because this is going to a location where dialup is difficult and costly and needs to connect/disconnect in a timely manner.
After a week of trying to get diald/ppp to act as expected in SME7, I have given up! After some tweaking of the diald.filter I managed to get it to connect correctly on demand, but couldn't get it to disconnect! SME6 is doing that fine and I have created a Bug report for 7.