Most airlines will reroute you on other airlines that they have ticketing agreements with. If they don't have an e-ticket agreement, or if AirTran does not issue paper tickets, they won't reaccommodate you. Airlines are very reluctant to issue checks to other airlines (as they must on Southwest) since it costs them considerably more than issuing their own tickets, and there may not always be someone on duty who has access to checks or drafts.