Exactly the same thing happened to me (with the X-Guard). Front one went on no problem. I had to take the rear one to the LBS to use their compressor to get the bead to sit. It's fine now.
Funny that. Don't think there's any correlation though as I had issues with the pro one with the rear wheel before too. May need to re-lay the tape on it. Ordered an airshot from Evans today so will see if that has any more success!
Exactly the same thing happened to me (with the X-Guard). Front one went on no problem. I had to take the rear one to the LBS to use their compressor to get the bead to sit. It's fine now.