Hi,
I have a short note on data binding: when source value is updated, the target value is not updated until all dispatcher processes the corresponding binding-related messages in it's message queue (or layout-related messages as well).

But, if this behavir does not suit your scenario, you can use one trick that I foun: you can make binding engine to update all bindings (with shceduled updates) manually. Here is some code to do that:

Assembly asm = Assembly.GetAssembly( typeof( System.Windows.Shapes.Ellipse ) );
string typename = Assembly.CreateQualifiedName( asm.FullName, "MS.Internal.Data.DataBindEngine" );
Type type = Type.GetType( typename );

PropertyInfo prop = type.GetProperty( "CurrentDataBindEngine",
BindingFlags.NonPublic | BindingFlags.Static );

object value = prop.GetValue( null, null );

MethodInfo methodRun = type.GetMethod( "Run",
BindingFlags.Instance | BindingFlags.NonPublic, null,
new Type[] { typeof(object) }, null );

// you can set false - than some bindings can be still left unprocessed
methodRun.Invoke( value, new object[] { true } );