Stan, again thank you for your kind remarks and I appologize for not answering your question in a more timely manner.
I have a few questions to ask to get a more clearer feel of your situation:
These large beams that span the home, how long are they and what is their dimension? Is there any pilings or supports that assist in the load bearing of these spans between the two cripple walls and the foundation wall?
Have you got under the home and put a long level to each span to check for stress or bowing? Have you put a long level in each room to check the level there? Stan, the key to this test is a very long level. The longer the level the more accurate the reading.
Is there a notable larger amount of cracking or signs of un-level in any certain room?
When your return some of these answers, I will again try to figure out what is happening.
Do you have a driveway that might show cracking? Do you have a patio that is showing any cracking?
Without your answers, I would feel that if the large beams spanning the distance of the home are not supported every 8 to 10 feet, I would do so. I would suggest to have holes dug under the home and filled with concrete. Then on top of this foundation or concrete form, I would obtain some house jacks and jack the home up carefully and then install permanent rail road ties or heavy lumber to support the beams. then remove the jacks and move to another spot.
Do you see any of these beams cracking and splitting due to stress? With the home settling, the beams will first crack on the bottom side.
Another idea. Get a marble or ball bearing, if you have wooden floors, and set it in the center of each room and see if it rolls any specific direction. Then try other rooms and see if a roll direction is the same way.
Another situation that is soo common in Texas is the change in the molecular structure of dirt. We go from heavy rains to nothing at all for months on months. The dirt changes density so often that settling takes place so much that one side may fall three to four inches.
Dirt is more dense with water, with water gone from the equation, the dirt compacts and shrinks. That is why in Texas the best thing that we do that other states and people laugh at us is the use of soaker hoses around our foundation to maintain a stable dirt foundation. have you tried watering your foundation and see what happens? This is a long long time experiment. you won't see any results for months. But it could remedy your situation. Remember, you must water the entire foundation at the same time and the same amount of water. If not equally dispursed, you have a worse problem.