applet works with appletviewer but not IE

I've been working on an applet that takes a flat file XML database, searches it using parameters specified by the user, and creates a new html page that contains the results. This program works perfectly in appletviewer, but every time i try to run it with IE, it refuses to do anything. I press the submit button, and it does nothing at all. It does display it fine, so I'm pretty sure it isn't a security issue. I have a good signed cab file. Does anyone know what might cause this?

[502 byte] By [ConlonP] at [2007-9-26 5:01:23]
# 1
Anything showing up in the Java console?Also, are you requesting the necessary permissions before actually issuing the privileged operation?
cknelsen at 2007-6-29 18:58:04 > top of Java-index,Security,Signed Applets...
# 2

> Anything showing up in the Java console?

Exception occurred during event dispatching:

java.lang.ExceptionInInitializerError: com/ms/security/SecurityExceptionEx

at javax/xml/parsers/SAXParserFactory.newInstance

at dbConnectApplet.actionPerformed

at javax/swing/AbstractButton.fireActionPerformed

at javax/swing/AbstractButton$ForwardActionEvents.actionPerformed

at javax/swing/DefaultButtonModel.fireActionPerformed

at javax/swing/DefaultButtonModel.setPressed

at javax/swing/plaf/basic/BasicButtonListener.mouseReleased

at java/awt/Component.processMouseEvent

at java/awt/Component.processEvent

at java/awt/Container.processEvent

at java/awt/Component.dispatchEventImpl

at java/awt/Container.dispatchEventImpl

at java/awt/Component.dispatchEvent

at java/awt/LightweightDispatcher.retargetMouseEvent

at java/awt/LightweightDispatcher.processMouseEvent

at java/awt/LightweightDispatcher.dispatchEvent

at java/awt/Container.dispatchEventImpl

at java/awt/Component.dispatchEvent

at java/awt/EventDispatchThread.run

Exception occurred during event dispatching:

java.lang.ExceptionInInitializerError: com/ms/security/SecurityExceptionEx

at javax/xml/parsers/SAXParserFactory.newInstance

at dbConnectApplet.actionPerformed

at javax/swing/AbstractButton.fireActionPerformed

at javax/swing/AbstractButton$ForwardActionEvents.actionPerformed

at javax/swing/DefaultButtonModel.fireActionPerformed

at javax/swing/DefaultButtonModel.setPressed

at javax/swing/plaf/basic/BasicButtonListener.mouseReleased

at java/awt/Component.processMouseEvent

at java/awt/Component.processEvent

at java/awt/Container.processEvent

at java/awt/Component.dispatchEventImpl

at java/awt/Container.dispatchEventImpl

at java/awt/Component.dispatchEvent

at java/awt/LightweightDispatcher.retargetMouseEvent

at java/awt/LightweightDispatcher.processMouseEvent

at java/awt/LightweightDispatcher.dispatchEvent

at java/awt/Container.dispatchEventImpl

at java/awt/Component.dispatchEvent

at java/awt/EventDispatchThread.run

ConlonP at 2007-6-29 18:58:04 > top of Java-index,Security,Signed Applets...