Yep also have some issues with the "Refresh Deviation".
When performing the setup in EQ mode, the S30 does rotate to point the camera up to check alignment.
However when you press this "Refresh Deviation" button, the new angles are significantly off..
It looks like the S30 may take the angle sensor data without correcting for the offset from true "up", as the S30 doesn't seem to check with stars straight 'up'. Which makes sense if there isn't something usable up there of course.
However it seems like each night I try to setup the EQ orientation, it may take a slightly different angle which results in different offset when you press the Refresh Deviation button.
I've seen a 2nd offset of over 10 degree which cannot be correct.