In other words, this whole thread could probably be summarized with this: if you're having this problem, re-calibrate. If the problem persists, try to manually re-calibrate using this video as a guide: http://www.youtube.com/watch?v=-GZdZX9f_-U. Failing that, and without the option of playing on a display that has no latency, adjust your gameplay.
I was technically doing the latter before I manually re-calibrated, and was still able to Gold Star songs and post some leaderboard scores despite the lag by just knowing when it was and wasn't safe for me to change lanes based on my calibration settings.
tl;dr: This isn't a bug. Re-calibrate, manually re-calibrate, and/or adjust your gameplay if you are experiencing this problem.