Hey folks, i have just completed my first java aplet game based on the old arkanoid 'not again',lol, anyways the game runs fine on my laptop which has ME and the 1.4 sdk/jdk blah blah blah installed yet when i run it on my desktop it wont start and if it does runs VERY slow, my desktop is a 1.4gig and my laptop is a p2 366, im doing this as part of second year at uni and am quite new to java, anyways here is the error from the debugger.

Set uncaught java.lang.Throwable
Set deferred uncaught java.lang.Throwable
>
VM Started: java.security.AccessControlException: access denied (java.lang.RuntimePermission modifyThreadGroup)
at java.security.AccessControlContext.checkPermission(AccessControlContext.java:270)
at java.security.AccessController.checkPermission(AccessController.java:401)
at java.lang.SecurityManager.checkPermission(SecurityManager.java:542)
at sun.applet.AppletSecurity.checkAccess(AppletSecurity.java:169)
at java.lang.ThreadGroup.checkAccess(ThreadGroup.java:287)
at java.lang.Thread.init(Thread.java:286)
at java.lang.Thread.<init>(Thread.java:332)
at JBreak.init(JBreak.java:48)
at sun.applet.AppletPanel.run(AppletPanel.java:347)
at java.lang.Thread.run(Thread.java:536)

and im getting a null pointer exception when the paint method is trying to paint the graphics, anyone spot whats wrong without me posting the whole code,lol,any help would be great thanks