Req. for some help with temp tables

Hi

We have a vendor delivered application running on postgres 9.1. It is creating temp tables per session. Currently the application group is reporting the that they are seeing a very slow response on the application in production and in the logs we see tons and tons of autovaccum of oraphan temp table cleanups. So we have the following questions.

1. How can we mitigate this performance degradation from the database side. The most interesting part is the application vendor doesn't seem to response in a timely manner. Also this application is connecting through glassfish.

2. What can we tune in the database to get this performance improve?

3. Every time the auto vacuum runs it pegs 1 CPU to 100%.

Please bear with these novice questions as I am very new to postgres...

Thanx,
Sam