Well, I finally discovered the problem. It was a side affect of the DataGrid being updated, and not the update itself. On an update, any changed data is sent to the TextBox and that part of the system was unaware to me. They were losing their focus because all objects were trying to refresh their data and not just the DataGrid. Also, the update to the DataGrid was being done through a DataTable, in which I never did need to refresh the DataSource variable. You simply have to: // Current Row DataRow row = _pumpTable.Rows[index]; // Edit Pump row.BeginEdit(); // Do Changes Here: row.EndEdit(); // Accept Changes row.AcceptChanges(); Thank you for your reply!

jschell wrote: there is no way to ensure that an action in thread 1 will only occur at point x in thread 2 :confused: What do you mean? That's what Monitors, Mutexes, (Manual/Auto)ResetEvents, etc. are for. The other example I posted demonstrates this using locks. Inside the receive callback the thread waits on the state object until no other thread is in a critical section using the socket. Likewise the Close method waits on the same object until all other threads have left their critical sections that use the socket. :badger: