poor SSL web mode performance

Is there a way to improve web mode SSL VPN performance?

Works great in tunnel mode but when attempting to use web mode (java applet) performance is very spotty. Text scrolling and sometime mouse movement is very choppy.

Using Fortigate 5.0 patch 12.

I'm hoping there is some Java heap size or other setting I can adjust someplace.

Any suggestions would be greatly appreciated.

Thanks,

Tom