No, it did not. And as I mentioned, I even tried deleting the index that it was using first, only to have the execution plan eventually revert to an index...

That's a good suggestion, and I tried it, but unfortunately to no avail. I also tried, in my dev environment, getting rid of various indexes that were in the way...

Glad to. Here they are, attached. I changed the encoding message at the top from utf-16 to utf-8 so they could be readable by a browser; perhaps SQL Server is...

Thanks for your reply. I agree that forcing a specific plan would not be the right thing, not least because I have no idea what all the implications would be....