Like any programmer, Steve has no doubt lifted perfectly good vb6 code directly into c#. Why re-invent the wheel when there's nothing wrong with the wheel you have.
While the syntax almost certainly changes in many cases, the algorithms often won't. Bugs will be a result of the algorithm far more often than they will be a result of the language syntax.
So if there is a bug in 7.1 code, and the responsible algorithm was lifted directly into c# as was, the bug quite likely exists in c# at current.
Even once we have c# it will make sense to post new 7.1 bugs. Even if they aren't repeatable in c#, the reason we can't repeat it in c# may be a rewritten algorithm. Or it might be that some other factor introduced in the c# version prevents or hides the erroneous outcome - in which case even though unverified, it would exist still, and posting it for 7.1 brings it attention, and gets it found.
Edit: ninja'd by Steve.