I think I'm going to put that on my list - maybe number one or two of things to check when I encounter oddities or breakages.
/wp-admin/post.php
I received a blank page (redirected to the above location - with a domain name, obviously) when updating a post - and it was due to a couple extra returns in the functions.php file.
Thank you google search!
Fixed... like a boss!
Embedded Link
The comment that was so helpful on that page was this:
<?php
Some functions.php code..
?>[some white space inserted here in error!]
I can remember bashing my head about that! I think some editors do that as well.
Darn white spaces!!