GX 20 - synchronisation with Outlook

My GX 20 "handest manager" software does not synchronise with Outlook, but reports successful synchronisation with Outlook Express!
Now my contacts (Names, phone numbers, email addresses) are not in Outlook Express but in the full Outlook version.

This is more a Windows problem than a phone problem as it seems...
I have checked the WindowsXP Internet Options, where the chosen/checked standard contacts software is Outlook (not Outlook Express), so at the moment I am not sure what else to adjust!

Anybody have an idea??