3400+ and up means it will work with 3400 and newer chips, does not mean it wont work with slower chips. It says 3400 because that was the fastest chip available when it was released. It is rare that a borad works with faster processors and not slower ones (as long as they are the same core/pincount...) Ie if a board works with a 3400 then it will work with 2800 - 3700, while if a board works with a northwood 3.4 it will certianly work with a 2.4...