I'm back again!
This time I'm trying my hand at plugin development.... So far I have one plugin working and I was working on another version of it when I ran into this problem.
The new module is a re-hack of the wikiplugin-sql module. My version is a bit more specific in that it's pretty much designed to return a given table of data from the Request Tracker application.
The plugin does work and throughout the debugging I was seeing normal results. When the function call ends I echo'd the return value just to see what was getting returned from teh function and it matches what I saw when I did the same thing in the SQL plug-in.
The plugin returns a formatted table similar to the SQL plugin. I've verified that the two outputs are identical but the odd thing is that when I finish the edit and then Save the page, all I get is a blank page. No source returned at all.
In order to get the edit page back I have to move/rename the plugin file to get the "No such module" error and then I can finish the save. After I save the page with the "No such module error" I can then rename/copy back the plugin file and the table renders just fine!
I've placed the plugin on a blank page all to itself and it still does it....
Not it gets even weirder; The earlier variant of that plugin that I have works just fine!
Any suggestions on where/how to troubleshoot next? As far as I can see the plugin has finished and returned the result to the wiki. I'm thinking something in the return file is messing with the page rendering....
So it turns out that duplicate function names are BAD! I had two plugins I was working with; the second of which was basically a clone of the first which therefore had duplicate functions. When tiki-editpage.php loads the functions in the plug-ins are enumerated and duplicate functions will cause the tiki-editpage.php to die. Once toggg passed this idea onto me, I renamed the functions and lo and behold the editpage came up just fine!
Thanks to toggg on the IRC channel for working with me on this.