Check the DataContextDataContext of the control and of the parent.
to help with debugging your bindings, check out Bea Stollnitz's blog
basically, assadd this xmlnsxmlns to your control
xmlns:diagnostics="clr-namespace:System.Diagnostics;assembly=WindowsBase"
xmlns:diagnostics="clr-namespace:System.Diagnostics;assembly=WindowsBase"
then add this to your bindingBinding(s)
{Binding .... , diagnostics:PresentationTraceSources.TraceLevel=High }
{Binding .... , diagnostics:PresentationTraceSources.TraceLevel=High }