互相 block 表示你要删除一个，要知道具体原因，可以 google 一下。

Block 都是 ebuild 的作者特意写进去的，一定有特别原因。

seamonkey就是mozilla的后继作品
没必要装两个吧

"equery belongs mozilla" and unmerged everything it listed.
Then put "-mozilla" in USE list in /etc/make.conf.
then did an"emerge uDtpv world". Here's the output:

# emerge -uDtpv world

These are the packages that would be merged, in reverse order:

Calculating world dependencies... done!
[blocks B ] www-client/mozilla (is blocking
www-client/seamonkey-1.0.2)
[nomerge ] media-video/mplayer-1.0_pre8 USE="3dfx 3dnow 3dnowext X
aac aalib alsa arts bidi bl cdparanoia cpudetection debug dga directfb
doc dts dv dvb dvd dvdread encode esd fbcon ggi gif gtk i8x0 ipv6 jack
joystick jpeg libcaca lirc live lzo mad matrox mmx mmxext nas opengl oss
png real rtc samba sdl sse sse2 svga tga theora truetype unicode v4l
v4l2 vorbis win32codecs xanim xinerama xmms xv xvid xvmc -bindist
-custom-cflags -livecd -musepack -nvidia -openal -speex -x264"
[ebuild N ] media-video/realplayer-10.0.7 USE="nsplugin" 6,494 kB
[nomerge ] gnome-base/gnome-2.12.3 USE="cdr dvdr hal
-accessibility"
[ebuild N ] www-client/epiphany-1.8.4.1-r1 USE="debug doc python
-dbus -firefox" 3,281 kB
[ebuild U ] gnome-extra/yelp-2.12.2-r1 [2.12.2] USE="debug
-firefox" 796 kB
[ebuild N ] www-client/seamonkey-1.0.2 USE="crypt debug gnome
ipv6 java -ldap -mozcalendar -mozdevelop -moznocompose -moznoirc
-moznomail -moznoroaming -postgres -xinerama -xprint" 35,162 kB
[nomerge ] x11-themes/gnome-icon-theme-2.12.1 USE="debug"
[nomerge ] x11-themes/hicolor-icon-theme-0.8
[nomerge ] dev-dotnet/gecko-sharp-0.6
[ebuild N ] www-client/mozilla-1.7.13 USE="crypt debug
gnome ipv6 java ssl truetype -ldap -mozcalendar -mozdevelop
-moznocompose -moznoirc -moznomail -moznoxft -mozsvg -postgres -xinerama
-xprint" 30,381 kB
[ebuild N ] app-misc/ca-certificates-20050804 91 kB
[nomerge ] perl-core/Test-Harness-2.56 USE="-minimal"
[nomerge ] dev-libs/openssl-0.9.7j USE="zlib -bindist -emacs
-test"
[nomerge ] dev-lang/perl-5.8.8-r2 USE="berkdb debug doc gdbm
ithreads -build -perlsuid"
[nomerge ] sys-devel/libperl-5.8.8-r1 USE="berkdb debug gdbm
-ithreads"
[nomerge ] sys-libs/db-4.2.52_p2-r1 USE="doc java tcltk
-bootstrap -nocxx"
[ebuild N ] dev-java/blackdown-jdk-1.4.2.03 USE="X alsa
browserplugin doc nsplugin -mozilla" 33,570 kB
[nomerge ] net-fs/samba-3.0.22 USE="cups doc examples libclamav
mysql pam python readline syslog xml -acl -async -automount -kerberos
-ldap -ldapsam -oav -postgres -quotas -swat -winbind"
[nomerge ] app-admin/syslog-ng-1.6.9 USE="tcpd -hardened -static"
[nomerge ] dev-libs/libol-0.3.17
[nomerge ] net-print/cups-1.1.23-r7 USE="nls pam samba
slp ssl -gnutls"
[ebuild UD] media-libs/libpng-1.2.8-r1 [1.2.12]
USE="doc" 0 kB
[nomerge ] dev-perl/DBD-mysql-2.9007 USE="-minimal"
[nomerge ] dev-perl/DBI-1.50 USE="-minimal"
[nomerge ] dev-perl/PlRPC-0.2018 USE="-minimal"
[nomerge ] dev-perl/Net-Daemon-0.38 USE="-minimal"
[ebuild N ] dev-java/blackdown-jre-1.4.2.03
USE="browserplugin nsplugin -mozilla" 13,224 kB

Total size of downloads: 123,001 kB

The only mozilla in there I see is the one it wants to merge...