Heres a step you might wanan try on oen of the bb devices itself:
1.On the Home screen, scroll to the Messages icon.
2.Click the trackwheel.
3.Click the trackwheel again.
4.Scroll to Options.
5.Click the trackwheel.
6.Scroll to Email Reconciliation.
7.Click the trackwheel.
8.Scroll to Wireless Reconcile.
9.Set the Wireless Reconcile field to Off by pressing
10.Click the trackwheel.
Give that a shot and see if you can wirelessly sync both ways after that.