How to fix screwed font display in password entry dialog? I don't have a single clue how my Mac OS comes to be like this.. 

Whenever I'm prompted to enter my password for admin rights to make changes to the system, my Mac OS seems to have a hard time finding the correct characters to represent the Roman alphabets it wants to display. Here are some screenshots regarding what it shows:





I suppose there is some bug (it is a Mac OS X version 10.7.5) or maybe I've accidentally deleted some system files required for the encoding..

This isn't really a big problem (since everything else works well), but as time goes by I feel the need to fix it.

I would appreciate if someone can provide me a solution.
So apparently it was solved by removing the fontd databases and deleting the files of conflicting fonts. (I guess the conflicting fonts were shown in Font Book?)

sudo atsutil databases -remove; atsutil server -shutdown


The password dialogs and force quit window are shown by processes owned by the root, so -removeUser might not work. launchd starts a new fontd process automatically, so atsutil server -ping is not needed.