It's not your imagination, and it's definitely not "normal."
Do a search for "throttle hang/rise" and you'll see what's been done on this in the last month or so.
I've had a terrible time with this myself. Good luck...and if your dealer wants to call my dealer, by all means, encourage that. Campbell Ford in Ottawa, Canada 613-725-3611...they're becoming experts on this, and they know it's not an imaginery problem.
