I did have another look at the seminars on Tuesday so here is the full hand I promised. The answer was straightforward: do not lead a singleton if you have no chance of a ruff. You cannot expect your partner to have an entry so leading a trump is probably best.

Declarer will eventually lose the HA and a diamond.

On a diamond lead declarer should be able to avoid a diamond loser and make his slam.

I am at an event up in Grantham at the moment and will be reporting on it when I get back.