I am the person that will be helping you today.
Without seeing the problem in action, it may be a bit difficult to pinpoint the problem. If you wish, I can remote into the computer system, analyze the issue quickly, and fix the problem. This particular problem have have several different culprits. My first thought is that you have some sort of quota setup to limit the amount of space used by the profiles or limit set on how many accounts it will store on the local machine. When you log into the computer via the AD authentication, is a profile created on the computer, locally? When you log in, what all is setup in the login script?
I will be standing by.
When you are ready to begin tomorrow, come back to this page and post a message. Be sure not to create a duplicate question; you can just come back to this page.