I had the same thing happen to me. I had believed for about 6 months that I had a "drain" someplace. Just when I "thought" I had it narrowed down, it changed. Very puzzeling UNTILL, I broke out my battery hydometer. Used to measure the batteries SPECIFIC GRAVITY. What I had found was a bad cell, just 1 bad cell. I tried to recharge it with a automotive battery charger to no avail. ALL MY PROBLEMS WENT AWAY WHEN I HAD THE BATTERY REPLACED. The battery was only 1 1/2 years old. Luckely it was purchased at a BMW shop and was still under a warrenty wich resulted in NO COST to me. BOTTOM line, CHECK THE SPEC. GRAVITY . I'd be willing to bet thats your culprit Bruce