Masked Domain & Admin Issues

Hi everyone,

After updating to the lastest version of WordPress (3.1.3), I’ve been getting issues logging into my admin backend.

Here’s an example of my current setup (links are invalid):
My wordpress files are located at: http://hostedfiles.com/blog/wordpress

I’m redirecting users to that page via my masked domain, http://masked.com

The site can be viewed without a problem when viewing from either domain, but, when I try to login via http://masked.com, the page stops loading. I can still login via the direct domain, though.

Any ideas as to why this is happening all of a sudden?

Thanks in advance…