A Problem Is Solved
When I upgraded my weblog software to Pebble 1.4-dev (CVS) 54 days ago, I noticed some inconsistencies between stand alone Tomcat 4.1.27 and the embedded Tomcat in JBoss 3.2.2 + Tomcat 4.1.27 in the way HTTP BASIC Authentication is handled. The net effect is that the trackback feature cannot be used under JBoss + Tomcat.
Simon Brown, the author of Pebble, has provided a work around for the problem. He has also written a nice summary of the issues involved at Java.Net.
I've just updated my Pebble to the latest CVS. And I think I'll send a trackback to Simon, and let him know that all his hard work is very much appreciated in this corner of the universe.