Outlook2010 64-Bit does not sync with Mobile 6.5

Hi there,

just installed Office2010 64Bit on my Desktop.
(Clean Install of Windows7 64-Bit Pro, no other Email-Software, not even
Windows Live Mail)

Sadly it says when my mobile phone (HTC Touch Diamond 2) is connected:
(Google Translate from German)
"there is no default email client available, or the current mail client can
not fulfill the messaging requirements. Run Microsoft Outlook and set Outlook
as default email client"

I tested 32Bit Outlook2010 on my Laptop - it works fine with sync - but not
the 64Bit Version.
Already read the complaints of other German users in the web - nobody seems
to have an answer.

It seems as this is a Windows Mobile Device Center Problem as this is not
64-Bit
http://social.technet.microsoft.com/...3-34ae6cee9a83

Can anybody please help?

Regards,
Marc