Janine, thanks, I got a bit further.
C.R., I'm not quite sure. When I set DISPLAY to localhost:0.0, no x windows apps are starting. When I change 0.0 to 1.0, they all work well. However, the problem below is the same with both of them.
So, I'm not quit there yet. This time the runInstaller script gets a bit further, and probably starts ok, because the last thing I can see is:
Object Monitor Status
---------------------
OK
However, no installer window is launched, the script just sits there.