I figured it out. The ghelp links are entered as "xref" links in mallard, but they should be "href" links: this example: <link href="ghelp:software-center">Ubuntu Software Center Manual</link> works.
** Changed in: ubuntu-docs (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/769027 Title: ghelp links are no longer working in recent builds of the 11.04 documentation -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs