Mathematica scroll problem

[VSJ <debian@terabytemusic.cjb.net>]

Hi,

I've a problem with the Mathematica 5.2 FrontEnd under Debian sid
(completely up-to-date):
When I load a large Notebook (i.e., large enough to have an enabled vertical
scrollbar) or Help topic, and I scroll down and then up, the window
contents become unreadable/trashed. The only way to remedy this is to
maximise and then restore the window size to force a redraw.

See screenshots of this behaviour at
http://tinyurl.com/aot3t

Maximising and restoring each time I scroll up is a bit annoying
(understatement).

Although Mathematica is using an ancient graphical toolkit, I don't think
that is the cause of the problem. At the university we're using the same
version of Mathematica (on Fedora Core) and everything works fine (even the
fonts look nice/clean/sharp!). But when I try to run Mathematica over SSH
with X-forwarding, I get the same problem as described above.

Thanks,
Karel