You may have a config error.  When you run the synchronizer, it places
a wingman.sgn file in the dropbox folder that it is assigned to use;
this folder is typically on the local computer.  If a sychronizer is
placing files in a folder on a remote computer, that indicates that
you've configured it so that the remote computer has your dropbox.
Typical configuration is that the dropbox resides on the local
computer.   Thus, if my machine name is MYComputer and the folder is
shared at C:\Dropbox, the FS Address should be \\MyComputer\Dropbox.

A few items:
First, there is nothing in the above code that tells the synchronizer
to shut down ONLY when it's done with all the synchronizations you've
asked it to do.  I run a star topology:  I have a replica farm at the
center of the star, and multiple laptops out in the field.  When a
field user decides they want to replicate, they do so only with the
center of the star.  Here is the code I use:

   Dim lngSyncStatus As Long
   Dim HistItem As Synch40.HistoryItem

   strExchange = sync.SynchIndirect("{F6...........9}",
synchTypeReplImpExp)
   Do Until lngSyncStatus > 1
           Set HistItem = sync.HistoryItemOfExchangeId(strExchange)
           lngSyncStatus = HistItem.SynchStatus
           If lngOldStatus <> lngSyncStatus Then
               Select Case lngSyncStatus
                   Case 0
                       'you'll be here while synchronization is
requested
                   Case 1
                       'you'll be here while sychronization is in
process
               End Select
           End If
           DoEvents
   Loop

   Select Case lngSyncStatus
       Case 2
           'you'll be here if you have a successful sychronization
       Case 3
           'you'll be here if your synchronization failed
       Case 4
           'you'll be here if your sychronization was cancelled
   End Select

Essentially what I do is set the synchronization up and running, and
then let it run until the lngSyncStatus variable goes above 1.  When
it does, I know that something has happened.  Then, and only then, do
I close the synchronizer and set it equal to nothing.

Also, because I'm running a star topology, I always know the
synchronizerID of the synchronizer that runs on the hub; for that
reason, I just feed that string variable in the rep.synchronizerID
statement.

See first comment; you shouldn't be writing to another computer's
folder/dropbox.