Thanks! I should've known that. In all the details of powering down the H bridge. I forgot.
I'll post my complete schematic here in a few days.
Trying to check anything that might draw current I thought about the 10K pull-up resistor on pin 1 of the Arduino. 5v through a 10K resistor = 500 uA. But maybe there's a lot more resistance in the Arduino chip when I put it to sleep?