Odd Mac OS X X11/WM problem

Hi,

I'm having an odd seeming problem and I'm wondering
if anyone would have any thoughts.

When the following holds:

1. Using a Mac OS X client with X11 started using the
quartz-wm window manger supplied by Apple, and
2. One SSHs to a Linux machine with X11 forwarding, and
3. One uses Matplotlib with the WX/WXAgg backend
on this remote machine,

then the plot window doesn't display properly on the
local OS X machine. The window clearly "exists" in the
sense that the OS X X11 server "knows" that there is
a window titled "Figure 1" (it appears in the "Window"
menu list), but it is not rendered.

Some data points:

1. This seems specific to the WX backend, since
the TkAgg backend works fine.
2. This seems specific to Matplotlib with WX, since
the WX demo.py application works fine.
3. This seems to have something to do with the
quartz-wm supplied by Apple, since I installed
Xorg as a test, and Xorg+twm worked fine while
Xorg+quartz-wm didn't.
4. This usage pattern used to work, although I
can't seem to recreate a working configuration
right now.

Thanks in advance for any comments,
d