IOS beginSynchronize method did not performing Background Synchronization

Hi group ,i used beginSynchronize method in my code. According to  info center document  beginSynchronize is used for Asynchronization .

The following link shows relates beginSynchronization.

http://infocenter.sybase.com/help/index.jsp?topic=/com.sybase.infocenter.dc01217.0212/doc/html/jwo1322598438259.html

.Following is my code

     SUPObjectList *uiy=[SUPObjectListgetInstance];

    id<SUPSynchronizationGroup> pop1=[InspectInspectDBgetSynchronizationGroup:@"IMAGES"];

                [uiy add:pop1];

                NSString *ol=@"mycontext";

                [InspectInspectDBbeginSynchronize:uiy withContext:ol];

According to the document beginSynchronization behaves same as Synchronization.Synchronization blocks the application where as beginSynchronization did not block the application.

So can any one guide me.