WCF Service and menu control

In my asp.net web application, I have aspx pages including a Status aspx page and a DataCheck aspx page that are navigated thru a menu control on a Master page.  On the Status aspx page I have a button which calls a WCF Service to run a stored procedure asynchronously.  The requirement is that while the asynchronous call is being performed the user should be able to navigate to other pages (i.e., the DataCheck page).  Here is the following code that I have on the button that performs the asynchronous call:
client.GetDataCompleted += new EventHandler<GetDataCompletedEventArgs>(client_GetDataCompleted); client.GetDataAsync(TableParams); client.Close(); To test this out I put a break point on the code in the client_GetDataCompleted and a break point on the first line of code in the page load event of the DataCheck page.  I clicked on the button and then clicked on the menu item t ...