I doubt there's anything in 3.11 to fix this, but the fact is that I'm
currently running on top of the nouveau/linux-2.6 tree
(http://cgit.freedesktop.org/nouveau/linux-2.6/), which is 3.11-rc6 + some more
commits. I have a couple of patches applied on top of that, but I don't think
any of them would matter for this case.

What other differences are there? I'm using 1920x1200, you're on 1600x1200. I
did get the "pan" thing from imagemagick's display command. I assume you would
get that too (if it didn't crash)? Do you use a compositor of some sort? I
don't. My NV18 has 64M VRAM, reports a 128M GART... how much does your card
have?

Can you get debug libraries in place so that you get symbol resolution on
nouveau_drv.so in the stacktrace printed by X?

BTW, if you don't want to constantly kill your "regular" X session, you can
start up a second X session to do your testing in. (Might seem obvious, but it
took me a little while before I thought of that.)