Vista - WMDC will not start up - EnableRAPIMgr(0x80070005) error

Hi, I am trying to use my Cingular 8125 (HTC Wizard) device to sync to my
Vista Ultimate computer. I installed the latest version of the WMDC
(drvupdate-x86.exe), in the prescribed manner (connect device, install
software) then disconnect and reconnect the device once the software is
installed. The device shows up as working fine in the Device Manager.
However, if I try to launch WMDC from the control panel, nothing happens.
Investigating the Event Log, I see the error "Failed to start the Windows
Mobile legacy device connectivity service due to EnableRAPIMgr(0x80070005)
failure (see data for failure code).". I have attached the full Event Log
entry at the end, just in case it is meaningful to someone.

I have tried un-installing, restarting, deleting Windows Mobile folder,
re-installing etc., a number of times (at least 5), and every time, the
result is exactly the same. Software installs fine, but WMDC won't start up.

What can I try next?

-Kal.
Log Name: Application
Source: RapiMgr
Date: 5/19/2007 12:37:35 PM
Event ID: 2
Task Category: None
Level: Error
Keywords: Classic
User: N/A
Computer: kal-bigdell
Description:
Failed to start the Windows Mobile legacy device connectivity service due to
EnableRAPIMgr(0x80070005) failure (see data for failure code).
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
<System>
<Provider Name="RapiMgr" />
<EventID Qualifiers="49152">2</EventID>
<Level>2</Level>
<Task>0</Task>
<Keywords>0x80000000000000</Keywords>
<TimeCreated SystemTime="2007-05-19T19:37:35.000Z" />
<EventRecordID>6297</EventRecordID>
<Channel>Application</Channel>
<Computer>kal-bigdell</Computer>
<Security />
</System>
<EventData>
<Data>EnableRAPIMgr(0x80070005)</Data>
</EventData>
</Event>

Did you ever get this resolved? I'm having exactly the same problem and can't find any information on it.