Confirmed. uscan(1) "In the case of an HTTP site, the URL obtained by stripping everything after the trailing slash will be downloaded and searched for hrefs"
Sometime between August 2007 and today, the link to the abs-guide from the debian/watch file was changed from a link to the tarball to a link to the pdf. Without that link, debian/watch fails. I have emailed the webmaster about the change and will update if there is any information.
