has anybody managed to get a sync with a Samsung GalaxyS running Android 2.1?

I have set up the Data Synchronizer and can login to the Webinterface as admin and as user. The connectors (mobility and groupwise) show as running in the webinterface.

I tried to set up my GalaxyS as such:
Add e-mail account
enter e-mail adress and password
manual setup: exchange account
domain-username: \mfischer
password: password
exchange-server: mymobility server
check secure connection and accept all certificates

When i click on "Next" I just get "Setup could not finish - Unable to open connection to server".

Any hints?