cannot increase Java memory heap...

Router and Security Device Manager in Cisco IOS Intrusion Prevention System Configuration Example [Cisco IOS Intrusion Prevention System (IPS)] - Cisco Systems says that I need to increase the Java memory heap size to be 256MB in order to configure IOS IPS. I follow the document and put "-Xmx256m" in the Java control panel and it still doesn't work. I enter in the values then restart Firefox (tried with IE also) and then visit the SDM. As soon as I go to the IOS IPS configuration screen it says I need to increase the Java heap size. Also, when I look in the Java control panel the value I set (-Xmx256m) is gone.
Has anyone had this issue? Is everyone else able to use the IOS IPS screen?
Has anyone had this issue? Is everyone else able to use the IOS IPS screen?
Comments
snickered,
Which version of the JRE do you have?
IOS: 12.4(15)T8
SDM: 2.5
JRE: 6 Update 11
Another weird thing is that Firefox doesn't work while IE does. All of this is on a 1760 router and my desktop is Vista Business x64.