[roypierce]

Igoldsmit, thank you very much for the extensiveness of your reply.
I could not try your first solution, because that program is not yet ported to Vista. So i tried your second solution. I added the entry in the registry. after changing 'micros~2' to 'micros~1', i did not get the error message anymore when clicking on the link to open the outlook object which was earlier synchronized with outlook 2003. Now the object was indeed opened in outlook.
However, the synchronization is still not working. I only see a flickering of the tab-window of UR. Then i thought, maybe the text url i am using is not correct. I went to the web site of Teamscope to download Linker for Windows, and then i red this message on their site where you can download Linker:
"OUTLOOK 2007 NOTE: Due to what Microsoft cites as security issues, Outlook 2007 disables the ability for Windows to use or recognize Outlook format links."
Maybe this is the reason why the synchronization is not working any more. When i have more time, i will try to investigate this further. Again, that you very much for your help.