FileMaker 9 remote access speed issues?

We recently had everyone in our company upgrade to FileMaker 9 from 8.5. Every workstation runs on Mac OS 10.4.10, and the database is accessed by about 35-40 people (peak). Roughly half of the employees are at the central office on a LAN that includes the Xserve G4 server hosting the database, and the other half are in different locations around the USA. Everyone uses remote access to login regardless of whether they are on the LAN or not. Those of us at the central office have had no problems, and the database even seems to run a bit faster than it did with 8.5. However, I have received complaints from several people who access the server externally, saying that it's running even slower than it was with 8.5 (remote access has always been pretty slow for those outside the LAN, but the drop in speed was significant enough for them to notice). From what I have gathered, it sounds like the speed issue comes when running scripts.

Literally the only change that has been made with regards to hardware or software is the upgrade from 8.5 to 9, and no major changes have been made to the database, yet the external users are saying it's slower.

Does anyone have any idea if this issue has come up elsewhere, or what the cause of it may be? I'm about ready to call Filemaker and demand that they take their 50 licenses back.