I'm running ObjectDock Plus Version 2 on Windows 7 64 bit and the docklet is working.
You could try removing the docklet from the dock and then adding it back to the dock. They may fix it.
Has this problem just showed up or has it never worked?
The docklet has 'broken' before, it may be that the version you are running has not been updated with a fix, you might consider updating to a newer version.
If someone from Stardock doesn't reply you may want to email support@stardock.com and provide a link to this thread.