In VIDA do you see the green bar 'connected' or the onragne bar 'disconnected'?
What's the status of the lights on your DiCE?
[Edit] Come to think of it I've seen that tab grayed out, I think I've just clicked on other tabs and then it works, but in my case I'm showing USB and Vehicle lights on the DiCE. Confirm your DICE is okay and working as expected.
 Confirmed that with my china DiCE and VIDA2010D the diagnostic tab is grayed-out until after I click one of the other tabs. Not sure if this is normal but not a problem for me, my DiCE/VIDA seems to work fine in my case. (didn't check yet if 2011D also does this)
I want to thank all of the post that helped me figure out the VIDA - DICE installation and configuration. I had almost every problem that is on the forum, including the non selection of the transmission!
In the end I de-installed and reinstalled.For my input, start out with all versions of NET.frame uninstalled, IE 9 installed and then do the install. The install will install the correct version of Net.frame, etc.