I think we found and fixed this over the holiday weekend. It wasn't showing up for everyone, but some people reported being unable to drag items around on ObjectDock.
The fix is an updated iprepair.dll that's part of IP 3.00a (which I've made available via Stardock Central or use the page at stardock.com/support to be resent the full download link). You'll need a reboot after installing it.
Failing that, Start / Run / regsvr32.exe /u "c:\program files\stardock\object desktop\iconpackager\iprepair.dll" would work around it, but then you wouldn't have the custom icons you've applied displayed inside other apps (where possible).