wp-admin works on host server, not from remote client

I have recently installed 2.6.2 fresh on my host server (one I own). When I view the new site (e.g. blog.mysite.com) from the server, it works fine. When I administer the site from the server (blog.mysite.com/wp-admin) I get the login screen, the login works, and I am redirected to the main dashboard page.

When I am at a remote location (i.e. not on the server console or inside my network), I can get to the blog.mysite.com/index.php page fine, and I see correct blog content. But when I try to go to blog.mysite.com/wp-admin/, all I get is a blank page.

I have viewed a number of the postings, and I have tried many of the solutions which don’t seem to be related.

Is there a flag somewhere that might disallow an administrator to access the wp-admin site from a remote computer?

Thanks in advance!