Hi Steve,
Actually historical user priority data should not really affect our matchmaking because we're using PRIORITY_HALFLIFE = 1 to turn it off and the base priority is the same for all users. With this setup I'd expect the job priority to fully specify the job execution order within a single users queue, and provide fair share when multiple users submit to the queue. But that is not the case.It's my understanding that even if you assign a job (or all the jobs from a user) to a group, this will not necessarily affect the user's base priority factor if the user was already in the system.
I suspect its a configuration issue on our side but I can't really find any setting that might cause this.
Cheers, Szabolcs