How to a pull a window to my second monitor that's above the current one when the menu bar is in the way?
I've just tried this in Snow Leopard (10.6.8) without issues...

Menu bar on bottom (primary) screen, secondary screen above and dragging windows between the two is no problem.

To do this, I've used the following configuration under Displays in System Preferences:



Check that your settings match and let us know how you get on.