Another user wrote to me with exactly the same problem about a month ago
(but on OSX10.3.9). I replied as follows:
My own problems with acgi-dispatcher were what led me to write peacePipe.
This was over 12 months ago now, and I don't immediately recall what finally
pushed me over the line wrt dispatcher. If you don't mind trying yet another
piece of software (which WILL conflict with dispatcher, as they both hijack
the .acgi extension in your httpd.conf file), I'd suggest taking a look at
His response indicated that with peacePipe in place of acgi-dispatcher, he
was able to run ConferWeb without problem. You can find peacePipe
elsewhere on this site (http://quicksilver.caup.washington.edu/software).