Ken, the High Yield Savings is capped: above $30K, the rate is reduced from 1.75% APY to 1.25% APY. Admittedly, it's not much of a reduction from 1.75% APY. As I stated previously, perhaps the higher rates after the cap are attempts to compensate for the 1% reduction in the High Yield Checking rate.
All these changes seem to have taken effect at the beginning of the current statement period, on 8/18/2010. The disclosured at the Sonoran High Yield Checking and Savings dedicated site
state that the APY is "accurate as of 08/18/10." The rates on Sonoran All Rates page (which don't include High Yield Checking and Savings rates) all say "effective August 18, 2010."
Perhaps Sonoran underwent massive rate changes on that date. At least the accounts I cared about saw the above-mentioned reductions. :(