Modifying an EJB in NWDI

I created an EJB Module DC, defined and coded a session bean, and activated the DC. I checked it out for further editing. I wanted to add a new business method. Normally I would do this by opening the bean into the editor, navigating to the Methods tab, highlighting Business Methods, and clicking the Add (or Remove) button. In NWDI, however, I find these buttons disabled ("read only"). I was able to add the method directly in the source, but then had to manually add the method to the local and remote component interface source also.

Has anyone else had this problem or a similar problem for other development objects (i.e., an editor function that works outside of NWDI but apparently not in NWDI)?