Further experimentation revealed that GroupWise 6.5.2 beta4 does not solve the problem. However it appears that if you play around with the custom settings of the Item Context toolbar, and move it into another position and then back again, the problem appears to ‘go away’. Changing the settings of the toolbars back to the settings which caused the problem to appear originally, did not seem to make it come back again.
By moving the toolbars and changing the custom settings (don’t know which is the key factor at present), something must be eventually written to the mailbox account which prevents the problem from recurring. This is why the problem appears to happen on new accounts or GroupWise client installations, and can disappear without apparent reason.
We need to pin this one down in order to help Novell reproduce the problem and fix the underlying cause.