Slipping trans?

have you had this ride for awhile? did it just start or has it always been. and last but least have you done anything (trans service or carb swap)? usually you can blame the kickdown linkage for just that- kicking down a gear under throttle issues (too early too late ect). assuming proper fluid level and kickdown adjustment I would suggest dropping the pan for service and check (replace) filter (to confirm it's not loose) and look in the pan for excessive amounts of fluff. (there will always be some). also if there is no magnet I would put one in the pan (can't hurt).