Bacterial rot? Hmm...was watering standing in the leaf axils? I know that you know better, but maybe the grower watered during a very cold spell?
How long does rot take to make itself evident after infecting a plant? I don't think we've discussed this on the forum, yet..
I'm so sorry, Julie. There is nothing more disappointing than watching a new plant dwindle away when there's not really anything you can do about it...except a Physan drench and maybe less humidity for a while? Maybe a small fan blowing on the plant, too.