Node selection problem in JTree

Hello,
I'm having a problem with the node selection in JTree. I have an applet with a JTree. When I select a leaf node, I have implemented a selection listener that handles the selection by opening a new URL. The selection works fine the first time I single click on the leaf node. Once the node is selected, if I single click on it again, nothing happens. I have to select a different leaf node and come back to the earlier node for the URL to open up again. I have tried many things like clearing the selection, handling the mouse click it etc to no avail. I'll really appreciate it if someone can help me out with this problem.
Thanks,
Mani