To pull this off you will need a second account on your Vista machine.
Click start and >> switch user. Login to your alternate windows profile.
Run WMDC. You will notice that it works on this profile. Once it finds your device, log off switch back to your main profile.
In my case this allowed WMDC to continue recognising my device and synchronisation worked fine.
i found this after more than a day on forums!
that worked only one time so the new one found: on the forums..
It requires to edit (or create) a DWORD registry key called “AllowLSP” on the desktop, in the following registry path:
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows CE Services]
The possible decimal values are:
0: Bypass LSPs for incoming and outgoing connections.
1: Bypass LSPs for incoming connection and use LSPs for outgoing connection.
2: Use LSPs for incoming and bypass LPSs outgoing connections.
3: Use LSPs for incoming and outgoing connections.