Keep losing my wi-fi connection when I plug my macbook into my tv.

Question

I just recently started plugging my macbook into my tv to use it as a dual display. Once I plug in, my wi-fi connection just disappears, and I can't seem to connect to anything. When I plug back out it's back to normal. Does anyone know what's going on here?
Specs:
I have 13-inch aluminum MacBook.
I use a mini display port to dvi/dvi to hdmi connection to my tv.
I have a 32-inch Vizio...not quite sure on the exact model number/year.
Using Snow Leopard as my OS.

Answer 1

I now have this problem where the only thing that changed was the model of my MacBook pro (and the OS version)
I was recently upgraded from a vintage late-2007 MacBook Pro (OS X 10.4) to a late-2009 MacBook Pro, new design, unified body (OS X 10.5.8). On the old model the DVI connector from my 20in Dell display (2405FPW, 1920 x 1200 @ 60 Hz) plugged right into the notebook and the WiFi (airport) was fine. On the new model I had to buy a mini-display port to DVI adaptor, and the wifi is not fine. Nothing else changed, the new notebook sits in exactly the same location a the older one.
I see the same symptoms as reported above. When the display is not connected, my wifi is fine; when the display is connected, the wifi fails.
I used iStumbler (release 98) to get some readings of signal and noise level. The signal is typically 69 - 71% regardless of configuration. When the display is not connected the noise is typically 11%.
Connecting things to the notebook:
When the display is connected via the mini-display adaptor and its power switched on, the noise jumps to 22 - 25%, occasionally 30%. (And of course, wifi fails.)
Connecting the notebook power cord does not affect the noise level or wifi.
Connecting a usb hub adds 4 or 5%, but wifi is OK.
Moving things around on the desk can affect the noise level (and signal) somewhat (maybe 5%), but not predictably. What is predictable is that connecting the DVI display almost always breaks the wifi connection.
Note: by 'break' I mean that connections to the internet time out; under system preferences, the OS still believes it is connected and shows its IP address etc. But, if I turn the airport off and then back on, it is usually unable to reconnect to the access point.
A blight on my otherwise wonderful MacBook Pro....
-C