Admin and users deleated from database

is this a bug? i tried to login to my account and was unable so i did password recovery to see if i had a account, no account so i went to phpmyadmin and checked but no users? i found a blog with the info on how to add user to mysql and created a account. got back into my wordpress dashboard and checked users and their is only my new account, but at the top of the page it says two admins(guessing my old one and new and contributors) but there not in the wordpress users page and they know they was not in the sql table as it was empty. is this a bug? or do i have o scared that my accounts been hacked? i have done a page site test with avag online and all ok – alls been fine up till now(just another point when i went to post i had no visual editor so i went to my profile but the box was not checked so i checked to remove visual editor save changes then unticked it and saved changes again and it is now restored.