NAV 2009 to CRM Online, Posted Sales Invoice to Invoice mapping extremely slow, filter also not working

Hi Everyone, 

We have made a mapping for NAV 2009 to CRM Online for Posted sales invoice to Invoice. the connector is very slow, writing 2.4 record in one minute. Whereas i got 250K records for invoices. Which take more than 70 days to synchronize it to the current state and in meanwhile more invoices will be generated. How can i make it faster, i already tried to change the retires entry to 3 to make it faster. Also tried using filter option for current year on posting date but the filter doesnot seems to work and bring same number of records.

Any help is appreicated.