Interesting.
Of all the times that I have installed I have never seen that.
Do you have a program that will allow you to look at your db/tables on your MySQL server? (MySQL Administrator, MySQL Work Bench, or Navicat Lite will do the trick.)
if you look at your ost_staff table, your admin account that you created should be in there. Check to make sure isadmin is set to 1. If not change it.
If that doesn't work please provide the following:
MySQL version
PHP version
Webserver OS and Webserver version
