I use the Huappauge 2250, which has a PCI card and an extension module. Each one is plugged via s-video to a seperate set top box. Running Windows 7 Ultimate WMC, in the setup it did find two tuners. It appears to also let me watch and record two seperate shows. I know this because when I had only one tuner setup, it actually warned me when I recorded something and tried to change the channel. Now with two tuners, I do not get that message however it appears to be recording the channel that I am watching. What is even stranger is when you look at your recording list, the show it taped is listed as the correct show, but when you watch it you notice that it is actually taping the channel you are watching. When you switch channel, that is also recorded.
thanks