you should be fine. my regularly scheduled connection time to DCA-IAH-MEX/TLC has been 31 minutes and never a problem.

try checking in via pda.continental.com instead of from the main OLCI. you will not get BPs but you will be successfully checked in and listed for any EUA.

when you exit the plane ask the gate agent to call your connecting GA to let them know you are on the way. they are supposed to already know via the computer, but it doesnt hurt. if you have to change terminals you can also grab a courtesy golf cart.