I understand perfectly why you find the mis-calibration so annoying. Here is a post I wrote about it a while ago:
http://badgerandblade.com/vb/showthread.php/324677-Rediscovered-my-Progress?p=4721248#post4721248
http://badgerandblade.com/vb/showthread.php/324677-Rediscovered-my-Progress?p=4721248#post4721248