Custom Control problem

Dear all,
I have created a custom control in C# (A panel with context menu's, event handlers etc already built in) in a dll, a control library. I've added this control to my user controls in my main application (a different project). I can then drag the panel onto my main form and resize it etc. The main form builds fine but when i run it and click on a panel I get an error "Object reference not set to an instance of an object". It is like the inputpanel object is not getting initialised properly. I create the object in the mainform and call the constructor to initialise it (along with InitializeComponent()). Does anyone have any idea what i'm doing wrong.
Thanks in advance