No subject

I've been able to find online is inconsistent and seems mostly
experimental, and I'm hoping to get a clearer answer.

We're running FreeNX Server 0.7.3 on Red Hat Enterprise Linux 5, with
students and professors connecting from a variety of systems and,
usually, not having problems.  What we're running into is the problem of
arrow keys not being mapped correctly for clients running on Ubuntu--up
arrow acts like Print Screen, etc.

What I'm hoping to work out is a) whether there is a known solution to
this that consistently works (without breaking anything for clients on
other platforms), or if we're going to have to experiment, and b) is it
possible to solve this entirely *server-side*, so we don't have to make
the students deal with it.

Andrew Verner