Isn't it just the powersupply ?
When i power my LXR from my bench supply at 9V, it does go up to 600mA when all the leds are on.
It also uses about 600 for a short while when powering it on.
So I can imagine that a cheap 500mA psu can't really hand…
I had the same problem on linux with gparted.
Instead of trying to find a solution, I fixed it the easy way by simply formatting the card in my camera.