Problems with screen management

I've been running Kubuntu/xfce on 3 Amd64 machines and have run into
serious problems with screen management in editors.  Moving the cursor
into the screen display will often cause the data on that display to
move around on its own or to become corrupted.

I have seen this in the THE editor, as well as nano and vi.   It makes
the editors unusable because once data moves around, you cannot treat
the data as being correct.

This is while running Kubuntu Beta 2 on an AMD64 machine.   Will try to
test it on an i386 machine as well.

A very serious problem for me.