Sub-domain wp-admin redirect problem

note that I have no issues when I access the wp-admin like this:
http://www.example.com/wordpress/wp-admin

it works fine when accessed like that but that defeats the purpose of using the sub-domain.

Urgent Help Needed!

I’ve checked the site url in the options table and followed all the trouble shooting directions under “redirecting” in the sites help section. It still wants to add /wordpress in the redirect query sting after trying to access wp-admin and being taken to the login page.

I have this test installation running at: http://wordpress.markmurphy.ca

I’ve pointed this sub-domain to: http://www.markmurphy.ca/wordpress

Both urls in “Settings” are set to http://wordpress.markmurphy.ca

Again, the issue is that wp-admin redirects to the login page. The redirect query string in the url when taken to the login page is set to http://wordpress.markmurphy.ca/wordpress/wp-admin

instead of what it should be:
http://wordpress.markmurphy.ca/wp-admin