I am not able to reproduce your result in my wifi environment. After a complete reflash of OS2006, a wifi search produces the usual "No Connections Available". Once again, I have to use the body-shielding technique before I can connect. Previously, a kernel reflash of OS2008HE had the same negative result.

In fact, nobody knows for sure that the problem is caused specifically by the presence of an n signal. It could be the total strength of 2.4 GHz radiation triggering a protective shutdown of the search and connect operations, with an unreasonably low threshold for the shutdown in OS2006 and the HE's. As long as the software remains closed, we can only guess at an explanation.

In your case, my guess is that your n router produces a signal very close to the threshold, and the speed kernel adds another element of instability, sufficient to shut down those operations.

We used to have a 2.4 GHz portable phone. When it was in use for a call, we could not use our wifi. (That was true for my wife's laptop as well as the 770.)