Don't believe your city is sold out for May 26 yet
Until http://www.cantstopthesignal.com/ is updated to reflect the correct date (as of 8:30 AM Pacific time it still says May 5 with info about the May 5 screenings) I would not believe that any cities are sold out. I heard that for the May 5 screening there were problems with Fandango and Movietickets saying that they were sold out for a city before they actually were, and then there were more tickets available to buy later.
So don't give up until cantstopthesignal has both the correct date AND says your city is sold out.
I am checking a bunch of different Firefly forums and updating my blog with links to where to buy tickets for various cities as they become available. I might have a link to ticket sales in your city before cantstopthesignal is updated: http://www.JacquelinePassey.com/