I insert either at 10 pm or 8-9 am to avoid the 2 am calibrations that Lloyd mentions
If the sensor wont calibrate make SURE the contacts are clean and the sensor is clean - if as lloyd said it bleeds some and the blood gets on the contacts the sensor will have trouble calibrating
You need to go buy some 357 batteries - they dont last as long as Abbott thinks - if the sensor is done and the battery status is under 50%, change it
using a sensor tends make me think that BG will change quicker than it does ..
Dont try to change your shirt after removing the transmitter
