now that I can get to my code from an actual computer:
function determineActions($urls, $preferred_prefix = false)
global $txt, $user_info, $modSettings, $smcFunc, $context;
edit- after looking through the code, I wonder why this error was not noticed before... because, in the core, unedited code, it looks like $scripturl is not actually defined in the determineActions function. It must have been added by another mod to my code and I missed it for the trick. Original code in the first post has been edited.