I was able to overcome this since I also used a database. I would give the visitor a "visitor_id" and I would pass this between domains (www.domain1.com?visitor=10) and when the visitor went to a new domain, the system would look up the username, password, and any other session variables that were set.
John
Darren S wrote:
I am having the same problem. The cookies do not stick between domains, which makes sense, but interestingly this means you can not pass in PHPSESSID= variables, because the cookies override them.