I have a laptop running Win7 that I use with a Dell docking station. I'd used it with XP for a couple years running dual monitors from the docking station, one from the VGA and one from the DVI.
After upgrading to Win7, the monitor that's on the DVI out is not detected, using "rigorous detection" or otherwise.
I've switched the cables to verify that it's not the monitor at fault-- but I can't find any info on why the monitor wouldn't be detected. I've got the latest and greatest Nvidia drivers installed (at least, as far as Windows update is aware).
Leaving the laptop lid partly open does allow Windows to detect the laptop's native screen as well as the VGA monitor, but never the DVI.
The monitors are HannsG JC199Ds.