I had the foot cramps
with my ds, and
my doctor said it was due to muscle fatigue and
swelling. He told me to try and stay off my feet a little more, and when laying down or sitting, try and position my feet so they were getting the most blood flow (don't sit on your legs, indian style, or lay with one on top of the other). I know those cramps can be severe, but what worked for me was if you are having one, flex your toes upwards (towards your knees), instead of curling them inwards.