Probably you're setting cookies under different domains.
www.yourdomain.com and just yourdomain.com are different domains and use different cookies.
Threads will use the
www.yourdomain.com - so make sure you consistantly use that domain for the cookie domain. All the photopost products have a place to enter your cookie domain. Make sure you've entered it with the www. Mixing yourdomain.com and
www.yourdomain.com will lead to loads of cookie headaches - so make sure you are consistant in all your links. <img src="https://www.ubbcentral.com/boards/images/graemlins/smile.gif" alt="" />
