It appears that some users are not being added to the wordpress database. Has anyone experienced this issue? I even tried to manually add the user and wordpress didn't add the user or throw and error! It's driving me nuts!
I am not sure which plug-in you are using, but amProtect does not add a person to the WP database until they log in. Simply filling out the aMember signup form doesn't add the member to the WP database. Maybe this is what you are experiencing...