With that machine NOT in production yet, pull it's network cable and work directly from it's console and see if anything changes...

I think this will work as well:
SELECT
    P.person,
    P.category,
    P.item,
    ISNULL(SUM(S.Qty), 0) AS Qty
FROM POSS AS P
    LEFT OUTER JOIN Sales AS S
        ON P.person = S.person
        AND...

Here's the RDL for the matrix-based cross tab report based on my query from my previous post.   Luis also has the right idea.   T-SQL can do it as a CROSS...

I'm thinking that it may be plausible to do this more easily in SSRS than in T-SQL, and I'm going to try it, but in the meantime, I'm posting the...

I would also be sure you set your error variables BEFORE you roll back your transaction, and I would NOT rely on yet another separate stored procedure to play error...

If I understand correctly, and I may not, you can't just impersonate a Windows account using a SQL login.   When I think about the security hole that would represent, it's...