2 SQL CE Native Error Codes (28037 And 28600) Freezing Up My Windows CE .Net Application???

I am running a .Net application (VB.Net, .Net Framework 2.0) on a Windows CE 5.0 handheld device. I am relatively having good success with SQL CE replication, however sometimes (2 users out of 30 every 2 weeks), are freezing up in the application.

Here is what CE SQl software versions I installed:
sqlce30.dev.ENU.wce5.armv4i.CAB
sqlce30.repl.wce5.armv4i.CAB
sqlce30.wce5.armv4i.CAB

I have a trace log in my application, and here is what pops up before the hang (warm rebooting the handheld works)


NativeError: 28037
SQL Msg: A request to send data to the computer running IIS has failed. For more information, see HRESULT.

NativeError: 28600
SQL Msg: The database is currently synchronizing with the server.


I am using a Thread to syncronize (microsofts built in class), as you can see I am well aware of 28600, it just means some other thread is already syncing, so I can wait until next time to syncronize. However, my users apps are freezing just after both error codes occur. Anything in the code below causing issues??? (maybe _repl.Dispose() is freezing up my handheld, because its freezing after this line of code (see below code):

"MTM.SPUD.Utilities.Utilities.Log("[DEBUGQLThread#" + threadId + "]: End of Thread Life.")"


Public Sub AsyncSyncronize(ByRef PendingData As Boolean, ByVal Publication As String, ByVal Subscription As String, ByRef LastSyncDateTime As DateTime)
Dim _repl As New SqlCeReplication()
Try
...
savedAsyncResult = _repl.BeginSynchronize(objDelegate1, objDelegate2, objDelegate3, objDelegate4, _repl)
Catch ex As Exception
Finally
End Try

End Sub

Public Sub OnSynchronizeComplete(ByVal asyncResult As IAsyncResult)
Dim _repl As SqlCeReplication = Nothing
Dim threadId As String = ""
Try
_repl = DirectCast(asyncResult.AsyncState, SqlCeReplication)
threadId = _repl.InternetPassword
_repl.EndSynchronize(asyncResult)
dataIsPending = False

Catch exce As SqlCeException
_repl.CancelSynchronize()
MTM.SPUD.Utilities.Utilities.Log("[DEBUGQLThread#" + threadId + "]: SQLCE OnSynchronizeComplete() NativeError: " + exce.NativeError.ToString + "SQL Msg: " + exce.Message.ToString)

dataIsPending = True
If exce.NativeError.ToString = "28600" Then
MTM.SPUD.Utilities.Utilities.Log("[WARNINGQLThread#" + threadId + "]: Will try again next time")
Return
End If

Catch ex As Exception
Return
'MTM.SPUD.Utilities.Utilities.Log("App Exception: " + ex.Message)
'Throw New Exception("EndSynchronize Failed: " + ex.Message)

Finally
MTM.SPUD.Utilities.Utilities.Log("[DEBUGQLThread#" + threadId + "]: End of Thread Life.")
If _repl IsNot Nothing Then
_repl.Dispose()
_repl = Nothing
End If
End Try
End Sub