jdMorgan - 5:15 pm on Oct 5, 2009 (gmt 0)

Sounds to me like the problem is with the declared "realm" of the cookies -- with how they are defined, and not with any DNS issues or "which physical server or documentroot is used."

If the cookies are defined to apply to all subdomains, then the client will send them with any request to *.example.com.

Cookies are sent based on URLs, and the client has no knowledge of physical servers, documentroots, or 'filepaths'.

If your cookie is defined with "path=/; domain=.example.org;" (note the leading period) then it will be sent with all subdomain requests and all resource requests. If defined as "path=/; domain=www.example.org;" then it will be sent only with "www" subdomain requests and all resource requests.

Jim

[edited by: jdMorgan at 12:34 am (utc) on Jan. 31, 2010]