Partition defintions open slowly

I'm working with partitions for the first time as we prepare to move to a new server and DOORS version.  When I create or edit a partition definition, it takes at leaset 40 minutes to select it, much less edit.  However since we are modifying our database design we are adjusting definitions, this performance level is unacceptable, especially if the wrong key is buffered and one open it decides to close the dialog prematurely.

Any suggestions on what many be causing this and how to improve performance?  We are currently using DOORS 9.1.0.2.