Hello Ujjwal Lahoti,
Unfortunately, this bug is available when you install WPF Demo from Q1 2010 installation. The good news is that it was fixed immediately and you can refer to our online demo
in order to see a working example.
Thank you for the feedback and please, excuse us for the inconvenience caused.
the Telerik team
Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items.