I am having a problem getting the Gzip compression working in Hummingbird.
I can not confirm if the mod_deflate is active as I am not sure how to do this. I have had other Gzip plugins working on the site that do seem to have functioned ok though.
The .htaccess is more or less empty apart from the Hummingbird code that has been added.
I don't have any other active plugins to the best of my knowledge that are enabling Gzip in any way.