Nothing is straightforward about Donovan McNabb these days. It turns out the $40 million he is supposed to be guaranteed in his new contract could turn out to be a mere $3.5 million. McNabb's agent, Fletcher Smith, clarified some of the details of McNabb's deal Tuesday. He says while the contract is worded so that it has ''$40 million in guarantees,'' the Redskins do have an option to cut McNabb at the end of the season with no further money due.