it isnt a silly question at all. most liekly the 3rd gear synchro is faulty. i would make sure the transmission has had the latest updated fluid in it (mtf 0063), the shift linkage is adjusted and check if the tranny has been overhauled. there was a problem with earlier trans. shifting problems and there is a kit to fix this. it may need a update kit. the dealer should be able to check on that for you. they will be able to pull up the warranty history for you.