Hi, paßt sonst nirgendwo richtig rein, wurde aber schon öfter in Threads angemerkt... Folgende Advisory kam heute von unserem Engineering:
Problem: Active Sync fails to recognize an established partnership with iPAQ Pocket PC.
Scope: All iPAQ Pocket PC connecting to a host via Microsoft ActiveSync v3.5 or later
Description: Customer may report that ActiveSync only allows their iPAQ Pocket PC to connect as a guest. This situation may be experienced with any current Microsoft operating system (host PC) running Microsoft ActiveSync v3.5 or later.
Resolution: Microsoft is currently examining this issue and will update when/if a permanent resolution is determined.
Customers that experience this issue should be advised to reinstall Microsoft Internet Explorer on their host PC. When Internet Explorer is reinstalled, certain software components that may be causing the validation failure are restored and the iPAQ Pocket PC will connect using the named partnership.
Note: Customers running Microsoft Windows XP with Internet Explorer 6 must perform additional steps to repair/reinstall IE6. Advise them to read Microsoft Knowledge Base Article (318378 ).
Viele Grüße aus München
Dieter
PS: Den IE neu installieren, damit Active Sync wieder läuft 
typisch Microsoft, warum einfach, wenn's auch kompliziert geht