User registration from wp-login .php not redirecting correctly.

I've noticed that the wp-login .php does not redirect to my custom login page. When you click on the registration link from wp-login, the result is "page not found". As I'm using the MU Blogs theme, I only encounter the wp-login page when I've signed out, so I suspect most visitors wanting to register will not encounter the issue, as they will use the registration link on the front page of the site. I don't know if this is a buddypress issue or not. Any insight into what is going on is appreciated. I've tried unsuccessfully to just hard code the wp-login .php to the correct page. Don't really want to do it that way, but will if we can't figure it out (and someone has the code changes to suggest). Thanks for all you do.