help with cache problem

I am having problems with wp-members. I am not sure it is this plugins fault, but I am posting here to search for help or answers. I recently installed w3-total-cache and liked it at first. Now I regret installing it. Members were no longer allowed to log in. After I removed, what I believe is everything w3 total cache touched, I am still getting the same behavior.

When I go to the page with the login, via shortcode on page, it says the user is logged in. After clicking on a link to go to another page, it shows the user not logged in. Going back to the login page, it shows me logged in. I tested this by going to the admin and indeed I am not logged in. Please help.

http://ww.wp.xz.cn/extend/plugins/wp-members/