Problem logging in to admincp
 

A common problem but I have searched and not come across a similar problem.

My site is hosted by a friend of mine as a subdomain on the server he uses and we have also bought an additional url that I want to use as the site address.

When using the long url to the subdomain everything works fine* however when using the web address (which currently points to the forum directory as I haven't setup a homepage yet) it will not allow anyone to login to the admincp.

The cookie path and domain are both set to the default settings.