I am also curious about the large exposure differences I see and what pobrien3 gets. pobrien3, is the moon a white without detail disc or can you see details. With a 300mm lens, the moon is a 2.75mm disc on the sensor. This may be too small to show blown highlights.
I'm also curious about the exposure differential.
Take this image, for instance (I know it's not very good, but never mind that):
Canon EOS 20D, 28-135mm IS @f/5.6, 1/200s at ISO 100, 100% pixel-for-pixel crop.
The Moon was almost as high on the sky as it gets in January.
I don't see how it's possible to get a decent full moon picture at f/8 and 1/10s, that's over four stops more than for the image above. And I even think I used a polarizer.