Chris,
That's weird. I see the same behaviour when there's an index tag. This looks like a bug to me. You could work around this by using an expression for the index tag. Something like INDEX ON IIF(lFlag, 1, 0) TAG lFlag. But you're probably better off removing the tag. As Hilmar mentioned, you may even lose performance.

>No question is stupid when you are dealing with something like this!!! Sorry you've had a bad couple of days too!!!
>
>I have discovered something... The field is logical and is indexed (I need it to be indexed!!!) but I thought "What the heck!!!!" and removed the index - MS Query now returns the reocrds!!!??? I have no idea why this has worked but it still causes me a problem as I need the field to be indexed... Mad!!!