Yep! What's happening here is that newer video cards and monitors can talk to each other and communicate what resolutions they'll do. So Windows doesn't show you the available resolutions of the new monitor until after you plug it in.

This makes it a spectacular pain when you want to force nonstandard resolutions, involving third party utilities and registry hacking. I'm still having trouble doing a particular nonstandard rez on one particular secondary monitor in my studio.