A recent AVG and Avast antivirus update is preventing DisplayFusion 9.9 from launching on some systems. If you're running into this issue, please update to the latest DisplayFusion 10.0 Beta.
DisplayFusion groups every Java-based app together in a single taskbar icon as shown below:
Windows 7 taskbar:
DisplayFusion 3.5 Beta 10 taskbar:
Some mouse over effects were IMO too transparent to actually recognize them if the application doesn't have the focus. In case of JDownloader and NetBeans 7.1 they're very different form the native Windows 7 taskbar. It can be hardly seen on the 2nd screenshot.
Just tested this out, and the Netbeans IDE and JDownloader taskbar buttons didn't get grouped on my Beta 10 taskbar. Are you running the latest version of Java and those apps?
Just tried 6.31 and the buttons for JDownloader and NetBeans are still separate on the taskbar. Could you post a copy of your DisplayFusion Troubleshooting info?