Rant: Mutually exclusive wireless and cabled network cards

Know what's really frustrating? Wireless cards that become automatically disabled when you connect a network cable. What's with that? In tech support, where I work, I sometimes need to remote control the client's PC to help set up the wireless connection. Of course, since we're trying to fix the wireless, we need to connect using a network cable while we do the work. Having the wireless unit then disappear, or become disabled and impossible to enable manually, we're up a dead end. Once the client removes the network cable, the wireless card is re-enabled or comes back online, but then we have no way of remote controlling the computer in order to configure the wireless connection. This is Catch-22 by design, and one of the most stupid features I've seen on a computer.

Now, you might of course argue that I could easily try to guide the client over the phone (I work on the phone exclusively, and have been told by many that I am very good at explaining such things), but having problems explaining even the simplest things to an extremely technically challenged and selectively deaf and blind client is why I need to do it by remote control in the first place.

I've been told that this feature (I'd call it an intentional bug) has been designed so as to improve the battery life of some laptop computers. However, it still happens when the laptop is connected to the mains, not running on the battery.

This occurs on a number of computers, mainly laptops, running both Windows XP and Windows Vista.