New proposals to ease our great mortgage meltdown keep rolling in. First the Treasury Department urged the creation of a new fund that would buy risky mortgage bonds as a tactic to hide what those bonds were really worth. (Not much.) Then the idea was to use Fannie Mae and Freddie Mac to buy the risky loans, even if it was clear that U.S. taxpayers would eventually be stuck with the bill. But that plan went south after Fannie suffered a new accounting scandal, and Freddie's existing loan losses shot up more than expected.Now, just unveiled Thursday, comes the "freeze," the brainchild of Treasury Secretary Henry Paulson. It sounds good: For five years, mortgage lenders will freeze interest rates on a limited number of "teaser" subprime loans. Other homeowners facing foreclosure will be offered assistance from the Federal Housing Administration.