OS X installs fonts in several locations.
Unfortunately, the Fonts window (which is shown by many applications when hitting ⌘+T) only appears to pick up the fonts installed in the “local” and “system” folders.
On the other hand, I’ve got a lot of user fonts installed (in ~/Library/Fonts). These fonts are shown as “installed” in the “Font Book.app“, and they work when used, for instance, from within XeTeX (which finds system fonts). Furthermore, I’ve got several fonts installed from MS Office, which reside in /Library/Fonts/Microsoft which also seem to be properly installed as far as Font Book is concerned.
But neither the user fonts nor the Microsoft fonts are shown in the Fonts window. Here’s an example:

– This shows that Century Gothic is picked up by the Font Book, but not from the Fonts window (from within “TextEdit.app”). The exact filename of the font is /Users/rudolph/Library/Fonts/Century Gothic and its file type is “Font Suitcase” according to Finder.
This seems to be a bug, since nothing in the Apple knowledge base article about fonts mentions this behaviour. Is this a known behaviour? How can I resolve this without moving all those fonts to the local fonts folder?
Note that I didn’t install the fonts by moving them to any folder – I installed them via the dialog that appears when trying to open a font.