Okay, the other week I installed a load of new fonts, but unfortunately a lot of them were corrupt, so I had loads of crashes and hangs. I used Font Book to validate all my fonts, but when I clicked the remove button FB always crashed (due to a corrupt font, no doubt...). I tried FontDoctor, which claimed to have sorted out all my problems, but although things had improved FB still reported over 2,000 minor errors. I've been working my way through the massive list in FB, checking and removing a few dozen corrupt fonts at a time. 'Serious errors' kept popping up that hadn't been there before, I'm not sure where these new corruptions were coming from. I've also, apparently, removed some of the standard fonts in the process (which weren't corrupt before all this). Everything on this page has become italic as a result, other pages are all bold, presumably the proper fonts have been removed . I now have 11 'minor problems' that won't go away, I check them and remove them, but when I validate again they're still there! I guess this is probably because they're in use? I've not tried deleting them via Finder, incase the world explodes, or something. (Geneva.dfont, Helvetica.dfont (and bold, italic etc), HelveticaNeue.ttc (and bold, italic etc)). I tried dragging the contents of /system/library/fonts/ from my MPB (which I haven't done anything to) into my MP fonts folder, in the hope of replacing any missing standard fonts and replacing any corrupt ones, but Finder won't let me do this at all, "The operation cant be completed because you dont have permission to modify some items.", with no option to authorise this with a password. Is that such as bad idea I shouldn't be trying it? Or is there some way I can get this to work?