Whitespace is not allowed after end of Markup Extension

While working on a new Silverlight project I faced this error during compile: Whitespace is not allowed after end of Markup Extension.

The issue it's related to the Binding: be careful white spaces before and after parenthesis.

Here is a sample of code to explain better what I mean (check hi-lighted part):

<ComboBox Grid.Row="4" Grid.Column="4" DisplayMemberPath="Description"

          ItemsSource="{Binding DescriptionsList} "
          SelectedValue="{Binding SelectedDescription, Mode=TwoWay}"
          SelectedValuePath="DescriptionId" />

Have nice coding ;)