I was using AquaTerm. After your reply, I tried X11 (with "export GNUTERM=x11"). The plot window pops up much faster (about 3 seconds), but the plot is not drawn immediately, taking about 2 minutes to be drawn. After the first plot window pops up, the second did not show up. I'm gonna try other terminals (I had to leave my office), but I am intrigued: are these slow plots commonplace on MacOS X?