To reproduce:
-Startup a Java app w/ a ScrollPane (the SymbolTest demo applet works well)
-move the cursor over the ScrollPane and rotate the mouse wheel to ensure that
 scrolling takes place
-click on the desktop to take focus away from the Java window
-wheeling over the window while it isn't active still scrolls the ScrollPane
-click on the window to make it active again
-(it sometimes takes another iteration of deactivating/activating the window before the problem occurs)
-wheel while over the ScrollPane. No scrolling. Oddly, deactivating the window causes wheel scrolling to work again.