Don, what sort of soils do you have in Ariz? do you have any clay in your mostly sandy soils?
Sounds like the corner of your home has settled more than the other parts and has "pulled" your home downward. What sort of footings were constructed for the cinder blocks to first sit on?
There is a company called Ram Jack, a professional foundation leveling company. I live in Texas and its a national chain. We have them here and have had our home jacked also.
The company drills down as deep as required to hit bed rock. Then it pours in concrete as a footing. Then the jacks are installed to achieve level all around. This is done slowly as to minimize the movement back to level.
They charge $500 per jack and recommend a jack every 10 feet around the foundation. In your case you migh just need this on three of the four sides.
How is your drainage, but then you rainfall must be close to zero. Do you have any trees close to your foundation.
Do you have a bed or garden up next to your foundation that you water more than other sides of the foundation?
I have found that, in our soils, if you have a garden or flower bed on one side of the foundation and that side gets much more water than any other side, that side will "rise" higher than the other sides. Its a molecular water and dirt thing that increases density.
Check out the situation and come back with more info.