Magento Multi Store Issue - login to secondary store redirects to main store

[almo136]

I have set up 2 stores under one Magento installation using this method:
[webdevster.com...]

Each store has it's own URL ie. [mainstore.com...] and [secondarystore.com...] (add on domain in cpanel)

If I navigate to to mainstore and then switch to secondarystore using the store switcher everything works as expected. I can log in on the secondary and remain there.

The problems arise if I navigate directly to secondarystore in the beginning. If I do this and then try logging in I get automatically redirected to [mainstore.com...]

Does anyone know why things only work correctly if I navigate to [mainstore.com...] and then switch to the secondary store?

[phranque]

i would compare the responses for both scenarios using a tool such as Live HTTP Headers plugin for firefox and look for clues in the cookies and response headers.

if you're up to it i would also look at the script that is executed when you submit the login form and try to find out where and why it is generating the redirect response.