The plugin was working like a charm until recently- when we noticed that users were not being logged in through IP anymore. After some tests, we quickly figured that caching was the problem.
We have disabled caching for some pages (like account and login) and it started working perfectly again. Now when IP-based access users do not get in automatically through the first visit (because of caching), they only have to click on the login or account page and get automatically logged in through there again (as there is no caching for these pages and the plugin loads normally here).
We will soon purchase the pro version to add an automatic redirection from the login page to the content after log-in. – This is not necessary for the plugin to function but it is a chic add-on solution.
