I know Virgin aren't very keen if you break a bond with another company to go and join them.
Assuming you had no outstanding bond with your previous employer and you gave them the full 3 months notice I can't see why Virgin wouldn't take you on. I don't see why taking a few extra weeks off between jobs would affect anybody. What did it have to do with FR when you were leaving the ME? Unless Virgin didn't like the reference they gave? Did you break a bond with FR to go to the ME perhaps?