Cable release won't work

I have a nikon mc30 cable release that is not working on my d300. i tried it on my husbands d300 and it works fine so i know the problem is with the camera. what do i need to do? thanks

I use a cable release on my D300 quite often and in all modes (timed, multiple or single exposures). I am not aware of any special programming or set up requirements. If the release works on one camera and not the other, then you are correct in your diagnosis.
Contact Nikon service. The number and info is on the Nikon web site.
There are two locations. I have had good luck with the El Segundo location.