When you start Groupwise when Desktop Effects enabled then it displays a blank grey window and nothing happens.
To fix or workaround the problem try to edit the groupwise client startup script to be as follows:
Alternatively, start Groupwise from a Terminal window as follows:
opensuse11:~ # /opt/novell/groupwise/client/bin/groupwise.sh -jvm=-Dawt.toolkit=sun.awt.motif.MToolkit &
This should resolve the problem.