This is a bug/poor wording on my part. I'll try and fix this for the next release.
In "Socialize Settings -> Inline Button Display Settings" you need to show/hide the post types you want to use Socialize on in general and not just inline. So to have an alert box with new inline buttons on posts you would need to make sure posts was checked for both inline and action buttons. Then, in the default button settings or the posts themselves, you just uncheck all inline buttons. This will hide the inline buttons and still display the alert box.
I forgot to change the wording when I changed the functionality which cause the confusion. Sorry about that.