I honestly don't know how or why it would make a difference.
But try using RelativeLayout.CENTER_IN_PARENT to get your ProgressBar into the center of your screen, rather than manually setting the top and left padding to be half the size of the screen.
So instead of:
mDiscoverLoading.setPadding((getView().getWidth() / 2) - (mDiscoverLoading.getWidth() / 2),(getView().getHeight() / 2) - (mDiscoverLoading.getHeight()), 0, 0);
use
LayoutParams lp = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
lp.addRule(RelativeLayout.CENTER_IN_PARENT);
mDiscoverLoading.setLayoutParams(lp);
Note that there are several different "versions" of the LayoutParams object, you'll want to ensure that RelativeLayout.LayoutParams
is the one you import since your parent is a RelativeLayout in this case.
I couldn't really tell you what is causing the padding to be buggy on the Xoom, but this is an alternate way that you can get the ProgressBar to the center, which seems to not be affected by whatever bug is causing the issue on the xoom.