Cannot execute null query

I got this error when trying to use a view, so I suspect that it was the
view definition query that was throwing this. I'd never seen this error
before so I did a search of the list archives and the newsgroups and web
in general and found nothing. From the pattern of it happening, my best
guess is that the underlying table had some data in it that was busting
the view query, but having never seen this before I don't even know
where to start looking. I cannot reproduce it at all, and since the
data in the underlying table is very fluid, I'll just have to hope to
catch it in action today. In the meantime, I thought I'd ask here to
see if anyone recognizes this error?

Thanks,
Fran