Three and four unit property now does require a big down payment.
That's because of the root cause of the mortgage sale problems. The entities buying the loans want super safe paper! Less than 25% down on multis are dangerous to mortgage buyers.
You can try going to a local savings and loan or bank that retains their own loans. They may be able to do a lower down payment or a cross collerteralization loan with they put a lien on another property in addition to the one you are buying in order for them to be comfortable.