M2B, one thing I noticed on a different post on the General Chat board was that you had noted your return date as May 5th. That may have been part of the problem as Air Jamaica doesn't fly on Mondays so no flights would have shown up and the Delta rep may have assumed they were cancelled in error. You may want to try for the 6th as Air Jamaica does fly on Tuesdays, and also Sat, Sun and Thurs only.
If you are looking for a cheap flight you may also want to try
www.skyauctions.com as they do auctions on flights and there was a flight to Belize on there for a date you choose.
Hope this helps!
In general I like the paper ticket in hand for a trip like this especially because it is a code share agreement so my itinerary doesn't show up on Delta.com like my Delta flights do. For an international flight like this I feel more comfortable with the physical ticket versus just a piece of paper for an e-ticket.
US AIr is having a sale now as well for folks still looking to book flights. Air Jamaica also has a fare sale noted on its webpage.
Andrea