I have installed gtk2-2.18.4-3.fc12.i686 in my system and I see this behaviour:
a) open two terminals in Gnome (all with mouse since now on)
b) select the first in the window list
c) double click its title bar to maximize
d) select the second in the window list
e) drag the title bar to change its position

Actual results:
The first terminal is focused on drag start (when mouse cursor changes to four-arrow), keeping moving will de-maximize it and the second window is being focused and dragged again.

Expected results:
Can change position of the second terminal window without de-maximizing the first terminal "automatically".

Notes:
 - it doesn't suffer this when doing c) with the "maximize" icon in the title bar, instead of double clicking.

 - I also noticed strange behaviour when trying to close the window, when I click the 'x' icon on the title bar it's not closed, but other window is focused. I didn't figure out how to reproduce this reliably, but maybe it's related.