I received an email about the ease of integrating Vista into an existing network since so many nightmare stories are circulating on the net.
I had no problem connecting the new Vista machine into a Windows XP based wireless network. I have three WXP systems (one desktop and two notebooks) in the wireless network and added the Vista notebook.
The important distinction is that the Vista notebook is new and not an upgrade from WXP. Many program and driver conflicts stem from upgrading to Vista. The network immediately recognized the Vista machine and vice versa.
The one WXP machine that gave me a problem was remedied by clearing the Wireless Zero Configuration settings and reinstalling them. Go to Start, Settings, Control Panel, click Administrative Tools, click Services and scroll way down to Wireless Zero Configuration. Double click WZC and usually the setting default is Automatic. This is where you can toggle it off, etc.