The window title on the update dialog of Plugin Manager should probably tell what it is, rather than mirroring the text shown in the progress bar. See screenshot.
jEdit 4.5pre1
Windows 7
1:52:34 PM [main] [message] Log: java.version=1.6.0_29
1:52:34 PM [main] [message] Log: java.vm.version=20.4-b02
1:52:34 PM [main] [message] Log: java.vm.name=Java HotSpot(TM) 64-Bit Server VM
Plugin Manager - Update dialog
fixed in rev 21094