I may be off base, but I believe for Central Users oyu may need to look up at the top right-hand corner of your screen when logged in.
You will see "PROFILE" with a drop down box...which shows your account and then the account holder of the person sending you the invite. Change to that account and you should then see the computer you are given access too.
I believe Warsawtech may be right. When you log into LogMeIn.com, check what profile you are on and switch profiles by using the drop-down bar on the upper right hand part of the window when you log in (right below your email, billing and account information).
If no such profile dropdown box is listed, make sure the person who invited you sent it to the right email.
Byron Daniel | Customer Support Representative LogMeIn, Inc. www.LogMeIn.com | www.twitter.com/logmeinhelp p. +1-800-993-1790