X11 draw issues, xterms exported to my machine

[jkwi]

I seem to be having X11 draw issues exporting
displays from a remote machine. Xterms will
be missing lines or blocks of characters that
appear only when I grab the window title bar to
move the window. Very annoying as I use alpine
for mail.

Could this be a BackingStore issue with Ubuntu
X11 server?

I'm tunneling with SSH, and have the same
problem whether I use Linux Putty or ssh from
the terminal directly.

I don't think it has anything to do with the
host machine. When I connect using my
windows box + putty + xming server
the exported xterms behave normally.

I've tried the nvidia 173 and 177 drivers.

No experience editing X11 server options.
I use xming or Exceed on windows.