You may need to open an SR to get a support rep to examine the application. This may require custom development to capture content menu items for this particular application. One thing you can try is using SendKeys after calling ShowContext menu. You may be able to select the item with a keystroke. If you do open an SR, please include the number in this post for tracking purposes.
I believe you will need someone to take a look at this with you on your machine. From your description, this sounds like it might require a custom development effort to support. If you do open an SR, be sure to include the number here for tracking purposes.
Harish, I have recommended to the Support Engineer to have your team upgrade to the latest version on a test machine. The new UI Connector feature would possibly allow you to develop a solution for this control without waiting for development support. I hope your team can take advantage of this feature to use with this control.