I have just realized I\'ve been coercing binding/dependency properties and not really fundamentally understanding the concept.
Heres the dependency property:
There are two ways to understand the reason of problem that you described.
At first - you should try to set property changed handler (in dependency property declaration) and put the breakpoint there. You will see whether your property is changing or not.
At second - you should check the type of dependency property owner.
Could you please show full xaml and codebehind?