Here in 9A the varieties listed do not do well. The one that really thrives here is a tall single petaled orange variety that I believe comes from the Dominican Republic. I don't know the scientific name. Butterflies love this one too.
So sorry; I only just saw this comment. It sounds like yours is a variety of C. sulphureous, maybe this one? http://davesgarden.com/guides/pf/go/218/
It's always interesting to me to hear different people's experience with essentially the same plant, so I appreciate your comment. Thank you.