Problem w/ .RESX files (MR)

I've created a custom control. And now I've something that prevents
me from using the designer to layout controls on my custom control. I
tried deleting the .resx file, thinking the VS would just regenerate
it, but did not.

Here's how I got the problem:

I created a new user control. I called it BaseControl.

I created another new user control. I called it DerivedControl.
After VS generated the .cs file, I changed the base class to
BaseControl.

EG:
public class BaseControl : System.Windows.Forms.Control
public class DerivedControl : BaseControl

Now I am unable to add controls to DerivedControl using the designer.
I have to manually create the code in .cs file. This gets really hard
to lay things out.

So, what I can do so that I can use the designer?

Thnx
Matt