Comment 6 for bug 687662

> You need to upload a new orig file instead of depending on one that was previously uploaded that since expired.

I worked around the problem by renaming the orig file, which I could do because the upstream version name wasn't crucial.
* renamed alephone_20100424.orig.tar.gz to alephone_20100424x.orig.tar.gz
* changed the version line at the top of debian/changelog to
  alephone (20100424x-0~maverick3) maverick; urgency=low
* rebuilt the package with "debuild ... -S -si ..."