Hmm... not the query dispatcher agian is it?
I've found that if you mistakenly put the query in the wrong file, or name it wrong, or don;t use the right naming convention, it tends to fail semi-silently.... i.e. it reports the failure of an empty query.
Might be worth checking your .xql files and ensuring you've got everything right.....
Or did you mean it does this before you've added any custom code?