If you could get some specifics such as what browser being used with what operating system it will help me figure out what possibley could be wrong.

Did they accept the digital certificate? It will pop up asking for permission to run the applet. If they said no it will cause problems and keep the applet from running correctly. Are they using any sort of advertisement controlling software that keeps various things from running in the browser such as javascript that opens windows?

As far as the applet/servers go nothing has changed but I intend on upgradding the applet soon.

Please try and get as much information as possible. I do want to make sure this works for as many people as possible. Thanks.