gnome-terminal (and presumably any application utilizing the libzvt
functionality) suffers from a slight issue with the scroll back buffer. 
Any time that the scroll region is changed via the ESC[<y1>;<y2>r command,
the scroll back buffer ceases to function correctly.

Scroll back functionality seems to end at a point just prior to the actual
change of the scroll region, and anything after that point is forgotten. 
It is difficult to explain exactly what it does, but if you use the
terminal for anything that changes the scroll region you can easily see for
yourself what happens.

To my knowledge, there are few (if any) terminal applications that actually
DO have a functioning scroll back after a scroll region change.  I wonder
if this is something that is impossible to work around, or if it is
something that is just often overlooked.