Vista Sync Center

I have a Motorola Q phone and when I installed Vista I installed the
latest Mobile Device Center. At first, each time I connect the phone via USB,
the Sync Center would open and do the sync. A while ago, instead of
opening Sync Center when I connected, it started opening a choice window about
getting pictures, etc. from the phone. I found some trouble-shooting
instructions about settings to Windows Live One Care and made those. It then
began working again for a few days but now the problem is back. Even
disabling the Windows Live One Care firewall doesn't help. I've found that if I
have the Mobile Device Center open at the time that I connect the phone, that it
detects it and does the sync and the Sync Center reflects that. But if
Mobile Device Center isn't open, whether or not Sync Center is open it
won't sync and it won't open Sync Center if it's not open. Any ideas what
else I need to do to configure this to work? Thanks!