<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by ht_redneck:
It probably means you're going through IAH, not HOU. I don't believe they even fly aircraft to HOU that have a FC cabin.</font>
Actually, CO launched nonstop HOU-EWR service with the 735 earlier this month. That service will now be discontinued on October 1.
I'd call CO and verify that they've switched you to an IAH flight and that the upgrade went through. Apparently some of these schedule cuts haven't been loaded into the reservations system yet, as the flights are still appearing in the schedules and website's booking engine.