Flash Remoting Issue

Hello,

I am using Flash Remoting, ColdFusion, and SQL Server for a project at work. The communication between the SWF file and database works for the vast majority of times. Yet some users say they can’t use the system. The say nothing happens at all when they request information from the database.

Does anybody know what could cause such a problem? I assume the problem is not related to the browser since only a very small fraction of users experience difficulties. Could it be a firewall issue? Proxy setting? Any ideas are much appreciated.