HypersomniacLive: A bit belated reply - there are two issues.
Both are relatively easy to work around and/ or solve.
HypersomniacLive: The first has already been mentioned by moonshineshadow above;
To fix this. Instead of showing a 404 page (which I think is bad design to begin with). Show a standard "This profile is disabled" message on Profile, Games, etc. when you or other uses try to view your profile if it has been disabled.
On the friends page, show the user the page even if the profile is disabled. For everyone else, show the above message. At the top of the page include a message up top that says something like: "Profile Disabled: To enable website functionality, only you can view this page. To allow other users to view it, please change your account settings", with a link to your account settings page.
HypersomniacLive: the second is that even in an enabled profile, friends with disabled profiles don't show up in the friends tab at all (which I assume has to do with how disabled profiles work).
Again easy to solve. Instead of hiding disabled profiles from everyone, hide them from everyone except for the account owner when they view their own friends page again for the sake of website functionality. Non-disabled profile and disabled profiles could even be broken into separate sections on the page, showing non-disabled profiles based on account settings and disabled profile friends only to the profile owner.