[gentoo-user] How do I switch from jpeg to jpeg-turbo?

[Nikos Chantziaras]

I unmerged media-libs/jpeg, and emerged media-libs/libjpeg-turbo. 
virtual/jpeg is installed.  Everything seems to work fine, and 
revdep-rebuild is perfectly happy.

But "emerge -uDNt world" wants to:
[blocks b     ] media-libs/jpeg:0 ("media-libs/jpeg:0" is blocking 
media-libs/libjpeg-turbo-1.1.0)
[uninstall    ]  media-libs/libjpeg-turbo-1.1.0
[nomerge      ] www-client/firefox-4.0-r2
[nomerge      ]  virtual/jpeg-0
[ebuild  N    ]   media-libs/jpeg-8c  USE="static-libs"

I'm confused. :-/