Oh there's still a good exterior ground to the dish and is also grounded to the cold water line. The only ground at issue is on the power plug to the 722.
I can rule out the ground as an issue when either:
A. your problem is solved
or
B. your ground issue is resolved. If there still is a ground problem at the power plug of your 722, then the ground is not correct. Overload of stray EMI and static will cause loss of signal. You seem to be experiencing loss of signal. If this wouldn't make any difference, I wouldn't mention it at all.