When I open Sybase Central I get an error "adaptive server anywhere plug-in failed to start-up properly and could not be loaded".

I have SQL Anywhere Studio 9 installed on a Win 2003 Server platform. I've also installed the latest maintenance update for Windows x86 to build 3320.

I've installed Sybase several times before and never had this problem. When I use the plug-in manager, ASA 9 is listed but when I try to load it I get the same error. Could my firewall be causing the error, or maybe a Microsoft security update?