Hey there. Sorry for the delay again. No, I have no answer except that you should take it up with HostGator if you want to find the solution (or better yet, find another hosting provider). I’m usually very agnostic when it comes to things like hosting etc, but I just got done working with another client’s project on HostGator and it was a nightmare! Truly was like wrestling with an alligator!!
They do some weird stuff with caching and it breaks quite a few things in WordPress – in my recent experience that is. If you find out from HostGator why this is broken, I will certainly fix it and I would be interested to know!!! The problem I ran into the other day may be very similar to your issue as it would interfere with some ajax, redirect and curl calls. Somewhere in the caching algorithm they use it outputs code in the header causing problems.
That is my best guess anyway. After 10 hours of working on it (when the project worked perfectly elsewhere) the client decided it was best to move to a dedicated hosting platform rather than the shared platform with HostGator. That fixed the problems immediately. During the investigation into that other client’s problems I found numerous articles of interest here: https://www.google.com/search?q=hostgator+wordpress+problems&oq=hostgator+wordpress+problems.
If I have time to get to it this weekend, I will try and upload my plugin to a HostGator site and see if I can narrow down the issue. It really has my interest peaked… I’m just working under a deadline now with very little time. Sorry for the troubles – I’d love to help you out though!!!