[Dltk-dev] Cannot view SDK source from within Eclipse

[Gerald Rosenberg <gerald@xxxxxxxxxx>]

Beginning to migrate my editor from DLTK 0.95.x to the new 1.X 
stream.  Installed dltk-core-sdk-S-1.0M6-200903161640-incubation.zip 
on Eclipse 3.5M6.

However, whenever I CTRL-click on a DLTK class file reference in the 
JDT editor, expecting Eclipse to resolve it and put up the source of 
the DLTK class, I am getting:

Source not found
The JAR of this class file belongs to container 'Plug-in 
Dependencies' which does not allow modifications to source 
attachments on its entries.

Seems to be a packaging problem with the DLTK SDK?  Is there a way to fix this?

Thanks,
Gerald