You sure? So you are just securing your category and your discount and/or on-board discount but not the price when you push your cruise out?
I have heard two stories on transferring "rebooked onboard" ressies. One, you keep your 10% discount and $200 onboard credit and apply it to whatever the current rate is for the new cruise. OR, I have also heard/read that when you transfer a ressie booked onboard, you get whatever the current "onboard rebooking offer" is.
For us, we moved our Cat 3 7 day Magic cruise April 2006 ressie booked onboard for 2A & 3C, to a grown ups only (2A) Cat 6 March 2007 3 day land/ 4day cruise. So we changed everything except the lead person on the ressie: # people, ships, cruises, categories, and dates. We recieved 10% off the current rate of the new cruise and kept our $200 stateroom credit. It was sad to give up our midship category 3, but the good news is that DH and I get a trip sans kids

and the new cruise is more than half paid for with the transferred deposit from the old cruise.
Now we were also told when we rebooked onboard last summer that the 10% discount and onboard credit would not apply to any "special" cruises ... I still have one more cruise "booked" for later in 2006. I am hoping to transfer that to turkey week 2007, but still waiting for rates & dates. THAT cruise will hopefully be back in Category 3 (yes, I have already faxed
DCL inventory control)
Come cruise with us that week!