OK, I've fixed the script issue. I had neglected to untick the pause button....
Still, I would like to know how to stop file maker from giving focus to a particular field when switching to find mode and/or to stop FM from dropping down my dropdown automatically upon entering find mode.
You can remove a field from the tab order. That may or may not be acceptable as this will also affect field behavior while in browse mode.
You could also write a script that enters find mode and uses go to field to place the cursor in a different field.