No orig.tar.gz or diff.gz with pdebuild

["Todd A. Jacobs" <nospam@codegnome.org>]

I'm trying to build some packages, and am using the following:

    pdebuild --auto-debsign --buildresult /tmp/$(basename $PWD) \
	--debsign-k 0x5005EF07 --debbuildopts "-D -sa"

The packages build properly, but despite the -sa option I'm not getting
the orig.tar.gz or a diff.gz file added to the relevant .changes or .dsc
files. I do, however, get a tar.gz file with the current source tree.

So, two questions:

    1. Are the orig.tar.gz or diff.gz actually needed, as long as a
       source file is still being built?

    2. If they're needed, what am I doing wrong here, and how do I get
       pdebuild to pass the correct command to whatever subprocess needs
       it?

Any help would be appreciated.

-- 
"Oh, look: rocks!"
	-- Doctor Who, "Destiny of the Daleks"