Blogs-mu registration problem

Theme was working fine and accepting new registrations from the home page. Then suddenly the registration function stopped working and simply linked back to the home page. Tried disabling all plugins. Tried manually typing in mydomainname/register but still it reverted back to the home page. Checked WP options to enable new registrations. Tried removing theme and reuploading. Nothing worked.

Love the theme, would appreciate some help. Thanks.