Greetings Marcia - and all others who've been following this saga.

Call off the dogs! Problem solved.

I created another grid on a similar form and got it to do what I wanted without complaint. Then I compared them. For some reason which I can't duplicate the grid builder had not assigned a controlsource to the columns, so naturally they couldn't display anything! I don't even know if it was my own stupidity (other than I should have spotted it earlier) as I can't figure out what - if anything - I did to cause the omission. The selected fields showed up in the builder as usual and it built the dummy grid properly with no different actions on my part.

So anyway, I've now removed the 'recordsource' references and everything works as advertised.

Thanks to all for your help and advice

Harry