TSP Adjustment

After a tune-up, IAC sensor replacement, and a bunch of cleaning (http://www.automotiveforums.com/vbulletin/showthread.php?t=638743) I've got the beast purring like a kitten again.

All the old SES codes are gone, except for the occasional blink of the SES light due to code 21 (Throttle Position Sensor Needs Adjustment). Anybody know how to properly adjust it?

I have played with the alignment of the sensor a little and it's behaving 99% of the time. If anyone has advice on how to properly set it, please let me know.

Cheers,
-Andrew

For anyone else who needs to know how to adjust the TPS:
http://www.avigex.ca/xport/dtc21.jpg