PLEASE someone!!!!!!!!!!!!
I copied the whole store to a much better host for a quick test, and it still spits the exact same errors. I've tried various modified contributions of the USPS file, and the original USPS file, tried every config setting I could think of, and NOTHING!
I just DON'T GET IT! It works fine for international, but NOT domestic, there are no switches, no differences, I can't possibly figure out what could be causing this. We've asked USPS multiple times and every time they say yes we're setup fine for domestic shipping, it has to be on osCommerce's end.
WHAT IS WRONG?!??!?!?!?!?!?!