Swing class MimeTypeParseException

[Brian]

I'm trying to use a utility that an engineer I know wrote using the
Java Swing & AWT classes. Getting some errors on startup & some
functionality (like copy & paste) are unavailable in the utility.
Before I go back to him I'd like to see if I can't get a little info
on what the problem may be & resolve it myself by loading additional
software if needed. The utility has a full local JRE install that it
uses.

Here's the beginnings of the errors I see on startup (the
HTTPTransformProxy items are our own classes, but everything else
should be standard JRE):

Starting HttpTransformProxy on port 8091
java.awt.datatransfer.MimeTypeParseException: Unable to find a sub
type.
at java.awt.datatransfer.MimeType.parse(MimeType.java:130)
at java.awt.datatransfer.MimeType.<init>(MimeType.java:47)
at java.awt.datatransfer.SystemFlavorMap.parseAndStoreReader(SystemFlavorMap.jav
a:324)
at java.awt.datatransfer.SystemFlavorMap.<init>(SystemFlavorMap.java:209)
at java.awt.datatransfer.SystemFlavorMap.getDefaultFlavorMap(SystemFlavorMap.jav
a:147)
at java.awt.dnd.DropTarget.<clinit>(DropTarget.java:59)
at javax.swing.JComponent.setTransferHandler(JComponent.java:2739)
at javax.swing.plaf.basic.BasicTextUI.installDefaults(BasicTextUI.java:277)
at javax.swing.plaf.basic.BasicTextUI.installUI(BasicTextUI.java:673)
at javax.swing.plaf.basic.BasicTextFieldUI.installUI(BasicTextFieldUI.java:56)
at javax.swing.JComponent.setUI(JComponent.java:449)
at javax.swing.text.JTextComponent.setUI(JTextComponent.java:267)
at javax.swing.text.JTextComponent.updateUI(JTextComponent.java:277)
at javax.swing.text.JTextComponent.<init>(JTextComponent.java:251)
at javax.swing.JTextField.<init>(JTextField.java:211)
at javax.swing.JTextField.<init>(JTextField.java:192)
at HttpTransformProxy.createHostUrlTextField(HttpTransformProxy.java:159)
at HttpTransformProxy.createAndShowGUI(HttpTransformProxy.java:125)
at HttpTransformProxy.access$000(HttpTransformProxy.java:20)
at HttpTransformProxy$1.run(HttpTransformProxy.java:71)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:178)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:448)