Ok, the first question is... Are you capturing the Resolution Category? In LDSD there is a specific category object for Resolution, but a lot of customers will actually link the main category that is used at creation to the Resolution object instead. This means that you only have to maintain one list for both, but you can report on each. Whichever way you are approaching this, the approach is to write the query based on the Resolution object and not Incident. As a general rule, if you want to report on information that is entered in a collection, always use that collection as the start point of the query.
Hope that helps.
Thats hit the nail on the head, I was going the wrong way about it.Have set it up and working fine after your mail.
Cheers for that.