Mainly yes, it has had the odd moment with the other gears too, but the 1st, 2nd and especially reverse are the bad ones.
From that info I'd say it is when the changes are not under high load accelleration.
Did you mention whether you had taken the REVO DSG software off and back on or not?
If you haven't taken the REVO software off, then maybe you could try it back as stock. If you have taken it off then I'd say it could be either the mechatronics unit, a faulty gear sensor inside the box or a worn selector. When My box was in bits, one of the selectors had wear on it......at 22k miles.
None of this can really help you (apart from diagnosis) as you already know that VW either change the mechatronics module or the entire box