ErrorProvider DataSource property - Object reference not set to an instance of an object

Short explanation of the problem:

My Install_Edit user control inherits WinPart. Controls on the Install_Edit form are bound to the InstallBindingSource, that is in turn bound to MyProject.Library.Install business object as its data source.

I am trying to set the DataSource property of the ErrorProvider of Install_Edit to the InstallBindingSource, however the list of the datasources for the ErrorProvider is empty and when i click on it I get the message "Object reference not set to an instance of an object".

Any help would be greatly appreciated.

Thank you,

TS