i am on season 3, disk 3 or 4. not too many shows ago, i thought they sealed the wormhole. and i dont quite recall for sure why - but it might have been to keep the dominion from coming thru. in this current episode, they are working with cardassian scientists to set up some communications array. and i think they just took the runabout thru the wormhole. i have been watching these shows in order. i dont recall anywhere when the wormhole was opened up again ? i figure i must be wrong somewhere ? the producers could not have made that big of a mistake !!