St. Louis law firm Carey & Danis said today that it has filed a class-action suit against UBS over the sale of auction-rate bonds. The suit alleges that UBS marketed the bonds as short-term investments even though they were really 30-year bonds. The bonds became illiquid in February when investment banks stopped supporting the auctions, and investors were unable to get at money they had expected to use for home purchases, tax payments and other purposes.

According to a National Law Journal article, attorneys have filed at least 16 other suits over the auction-rate issue. When I was reporting a column about an auction-rate victim, however, other attorneys told me that such cases would be difficult to prosecute. The problem is that, while investors can’t easily get their money out, they may have trouble proving that the bonds have fallen in value. In fact, some investors are earning handsome rates of interest while they wait for the bonds to be redeemed.