Problems with new subdomain
 

As part of a general update of my site, I set up a subdomain for the forums - so where the forums were accessible at www.bmw-driver.net/forum, I provided an alternative domain - forum.bmw-driver.net.

Few things - firstly - I presume this is within my licencing, as its not a separate forum or domain?

Secondly - (and obviously dependent on the answer to the first question) - users can see attachments if they use the old URL, but can't see them if they use the new one?

After doing a few searches, it looked like custom cookies could provide a solution - I made a feeble attempt which resulted in me not being able to log into admincp.

Anyone able to shed some light on this?