datacursormode problem solved. Finally.
How stupid of me!!!
I have been trying to figure out why I could use datacursormode with everything except my data in my GUI (my data outside of my GUI worked fine). It turns out that somewhere in my screeds of nicely commented code I had helpfully set my data in my GUI to "Unclickable." Apparently I did this to speed things up (thank god I actually commented the code in the first place). This is why nothing happens when I try to click it with the data cursor! I have been struggling with this for weeks! Aaarghhhh!!!!!!
At least I know now...
Useful piece of information: datacursormode does not work on things that have "HitTest" set to "off".Now, maybe I can make some progress...