X.org freeze 100% CPU after gnuplot exit from xfce Terminal 0.4.8

[Christian Leitold]

Hello,

I have already posted this problem in the gnuplot newsgroup
(comp.graphics.apps.gnuplot/PIdXzp-uIl0), however I got no reply
whatsoever, so I like to try my luck here since the problem might
equally well be related to the xfce Terminal. The problem is as
follows:

I use gnuplot interactively  with the QT terminal on Debian testing /
wheezy amd64 and XFCE as desktop environment, in xfce Terminal 0.4.8.
Whenever I exit gnuplot (whether by CTRL-D or typing "exit", there is
a SOMEWHAT SMALL chance that immediately after that, my X.org freezes
and takes 100% of the CPU. The mouse cursor turns to "text selection"
and I can still move it, however, X does not respond in any way apart
from that. By "somewhat small" I mean, roughly estimating, something
in the order of 1 in 10 or less.

The whole thing is rather annoying, since my only "solution" so far is
to login from remote and kill X.org, which of course also kills all
open windows etc. I also could not find anything like that on the web
so far. What I know is, that a) exiting gnuplot is so far the only
thing which has triggered this behavior, and b) it MIGHT be related to
the (unfree) Nvidia drivers, as I have this problem since upgrading
these.

Any suggestion what might be problem here? Is there any way I might
debug it, or at least find out what program is causing it? gnuplot,
xfce Terminal, X, the Nvidia driver, ...? Where should I look first?
Ideally, I would of course like to pin down the exact point where the
freeze occurs, in order to fix the problem, or at least avoid it in
the future.

Thanks!
Christian