Have you activated your key in the UPDATES page under settings?
Squarestarmedia, I have the same problem. The solution would be:
1) Radio Button
2) Tick required
3) Fill in options
4) Default value: null
This would have a null value in the field, neither radio buttons will be checked and the form won’t validate unless the user selects one of the radio buttons.
I found it elsewhere in this forums, I didn’t come up with it. This is not a definite fix and I believe this bug should be adressed (if no default option is given, radio buttons should remain unchecked!)
Cheers