Most F2 aficionados know that the preferred motor drive setup for that camera is the MD-2 motor drive with the MB-1 battery pack. The MB-2 battery pack is more commonly found on the MD-3 motor drive. But the MB-2 battery pack will work on the MD-2. My question is how well. Last week I fell into a great deal on an MD-2/MB-2 combo. Both the drive and the battery pack are almost mint. I used to own an MD-2/MB-1 combination, and really was fond of it, so when I picked up this MD-2/MB-2, I figured that two fewer batteries (8 vs 10) shouldn't affect performance all that much. But now I wonder. I had film already in my F2 when I mounted the drive to it, and after mounting it, I tried the drive out, and it seemed to work fine. I only fired off a few shots in Single mode, though. Went out today to look for something picturesque to shoot, and the drive behaved normally until the roll ran out. Hit the film rewind switch, and it rewound, but sounded a bit like it was dragging. Once the film was down to just the leader being exposed, it stopped -- more or less -- so I opened up the back, only to dscover that the leader was still in the take up spool. Closed the back and tried again. Nothing. Rewound the film manually the rest of the way. I loaded in a fresh roll of 36 exp, and went to advance it to frame one. At first it made the motor drive noise, then it gradually slowed down and began to chug. For the first few frames, the drive wouldn't wind forward all the way, and the red light next to the power rewind lever glowed faintly. Rotating the lever slightly to the right got the light to go out, and finally moved the film to the next frame. This continued for the first four frames or so, at which point the drive felt like it was getting its second wind. And within a few more frames, it was back to normal. The batteries are brand new, but it's almost as if they were dead. Then came back to life somehow. So what I'm wondering is -- are the power requirements for the MD-2 too great for the 8-battery MD-2 pack to work properly?