NOT THIS AGAIN!!!!!!!!!!!!!!!!!
It is a cookie problem, browsers have problems with cookies if you don't connect directly to a site. Thigs like IP masking, domain forwarding, URL masking, etc. will all prevent web browsers from correctly reading back in cookies.
The reason for this is that for security cookies can only be read back in by the site that set them, when masking IP address, using frames, etc. web browsers often can not correctly associate the cookie with the site.
Right I said it again for the 100th time
Please read through other posts first.