FF and IE browser crash with Java Runtime Parameter set to -Xms(>96m)

Platforms tested - win XP
Browsers tested - FF, IE
Build tested - any 6u5 build

Steps to reproduce:
Install JRE
Open Java Control Panel and set java Applet Runtime parameter to -Xms256m (anything more than 96m)
Open IE or FF browser
Open the Java Console (Tools -> Sun Java Console)
Browser will crash.

Note: -Xms may not be a valid runtime parameter, but the browser should not crash. If we specify any arbitrary string value, the browser does not crash. It only crashes with -Xms(>96m) values. It's not reproducible on all the machines, but can be consistently reproduced in some of the machines.

Machine to reproduce:
host name - hongkong
vnc passwd - vnc