Subdomain Sessions

[eluser]Aaron L.[/eluser]
Hi Esra,

Thanks for the reference. I looked at it and it seems to be discussing how there can be multiple domains/subdomains (but not multiple installs). This is all good information, but I already have this successfully working on my site.

The problem is that when a user logs-in to one site (say the sub.domain.com), then goes over to the main domain (domain.com which is the exact same ci install), the session isn't recognized.

I noticed one post saying that xml-rpc might need to be used. Is this correct?