okay, I've debugged the issues. folks shouldn't have quite as many problems now. however, read on, as there are some important notes. (more has been added to the README to keep this all in one place)
First, I haven't been testing on anything but 1.5.1 or later. If you are running builds before 1.5.1, I can't guarantee compatability -- but this new version TRIES to do just a little bit to be more compatible with 1.5 release.
Before 1.5.1, the admin menu hooks worked differently. So I quickly hacked in that if I get double-included from the admin interface, assume I need to call my own admin panel function. That got the panel showing. Then I needed to handle a WHOLE bunch of other cases that were getting screwed up by the double-inclusion.
Obviously, the plugin also assumes all the following actions/hooks are in place in admin or site themes:
Without those actions/hooks, I can't automagically insert myself. If your theme is missing the wp_head/wp_footer hooks, you'll need to make them yourself.
I also need full write privs to the wp-content folder for the script to be able to write the data file out. In Marc's case, it needed world/public write privs added, then worked fine.
There was also an issue that I was grabbing the 'home' url instead of the 'siteurl' wp path. Turned out Marc's home url included 'index.php' versus just the path. I now grab the siteurl, which I assume should never reference a code file directly.
Marc's site was completely functional with my new code. I'll upload it as 1.0 to my site right now, since that seems to have caught the major issues, and will add notes to the readme as well.
Too bad I couldn't have caught this all a few days earlier -- some of the contest judges might have all these issues. Well, they can always grab 1.0! ;) ;)