today my PHP i-Stats counter all of the sudden started to not show any online visitors. In the sumary page is showed Online Visitor/s without anything, it showed nothing so the counter stopped working, i tried to fix it by re-installing all the files but that didn't work. so to fix this error this is what i had to do to fix it why i wasn't showing any users, this is what i did to fix:

1. i logged into myphpadmin Mysql database, and in the is_session table, i empty it. ( TRUNCATE TABLE `is_session` )

2. once i deleted all the fields in this table, my counter started working again.

so if you are having problems with your counter is not counting, this is what you must do.