I'm trying to run a program on a remote Sun workstation on my Linux/KDE desktop. When I connect via ssh and run the program, it starts OK. But the GUI consists of several windows one of which contains graphics. When I have this graphic window active, my whole desktop becomes strangely coloured, but when I activate one of the text containing windows again or some app from my system, everything changes back to normal.

As a workaround, I started a vncserver on my local machine, then a vncviewer. When I connect via ssh and start the remote prog, everything behaves normally. But I didn't succeed in changing to a lean window manager instead of KDE which I'm using a my primary desktop.
So the whole procedure of connecting takes a long time since I have to wait for the second KDE session to start.

Can anyone help me with one of those problems?