Airport in OS X stops working a few minutes after loading Guest OS in Parallels!

I have an extremely strange problem:

After firing up Parallels, using Bootcamp, running Microsoft Vista Ultimate, networking initially seems fine. Both Mac OS X & the Vista OS under Parallels get internet (using all the default settings for network sharing under Parallels).

A few minutes later, suddenly the internet will stop working on BOTH OSs. Worse yet, the little Airport icon will show that it's connected to my wireless network, but WILL BE UNABLE TO DETECT ANY OTHER NETWORKS that happen to exist. If I disconnect from the wireless network at this point, and then try and reconnect, Airport shows me that there are no wireless networks available! Only a hard restart brings Airport back to recognizing wireless networks...

Very annoying, troubling, etc. Anyone else experienced this?

I'm running the latest & greatest of Parallels (5060).

Thanks in advance,
Rishi