In all previous versions of Firefox (<=1.5.03) when the cursor is in a text input field the middle mouse button pastes into that field. With 1.5.04 it now treats the clipboard as a URL (which is what used to happen with the middle button when not in a text input field) which it attempts to visit. emerge --info Portage 2.1 (default-linux/x86/2006.0, gcc-4.1.1/vanilla, glibc-2.4-r3, 2.6.16-gentoo-r9 i686) ================================================================= System uname: 2.6.16-gentoo-r9 i686 Intel(R) Pentium(R) 4 CPU 3.20GHz Gentoo Base System version 1.12.1 dev-lang/python: 2.3.5, 2.4.3-r1 dev-python/pycrypto: 2.0.1-r5 dev-util/ccache: [Not Present] dev-util/confcache: [Not Present] sys-apps/sandbox: 1.2.18.1 sys-devel/autoconf: 2.13, 2.59-r7 sys-devel/automake: 1.4_p6, 1.5, 1.6.3, 1.7.9-r1, 1.8.5-r3, 1.9.6-r2 sys-devel/binutils: 2.16.1-r2 sys-devel/gcc-config: 2.0.0_rc1 sys-devel/libtool: 1.5.22 virtual/os-headers: 2.6.11-r5 ACCEPT_KEYWORDS="x86 ~x86" AUTOCLEAN="yes" CBUILD="i686-pc-linux-gnu" CFLAGS="-O2 -march=nocona -mtune=nocona -pipe -ggdb" CHOST="i686-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/kde/3.5/env /usr/kde/3.5/share/config /usr/kde/3.5/shutdown /usr/lib/mozilla/defaults/pref /usr/share/X11/xkb /usr/share/config /var/bind" CONFIG_PROTECT_MASK="/etc/env.d /etc/eselect/compiler /etc/gconf /etc/revdep-rebuild /etc/terminfo /etc/texmf/web2c" CXXFLAGS="-O2 -march=nocona -mtune=nocona -pipe -ggdb" DISTDIR="/usr/portage/distfiles" FEATURES="autoconfig distlocks metadata-transfer sandbox sfperms splitdebug strict" GENTOO_MIRRORS="http://ftp.romnet.org/gentoo/ http://ftp.du.se/pub/os/gentoo http://mirror.datapipe.net/gentoo http://gentoo.ynet.sk/pub http://distro.ibiblio.org/pub/linux/distributions/gentoo/" LANG="en_GB.UTF-8" LC_ALL="en_GB.UTF-8" LINGUAS="en_GB" MAKEOPTS="-j3" PKGDIR="/usr/portage/packages" PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress --force --whole-file --delete --delete-after --stats --timeout=180 --exclude='/distfiles' --exclude='/local' --exclude='/packages'" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage" PORTDIR_OVERLAY="/usr/local/portage" SYNC="rsync://rsync.europe.gentoo.org/gentoo-portage" USE="x86 X a52 aac aalib acl acpi aim alsa apache2 arts audiofile avi bash-completion berkdb bitmap-fonts bonobo browserplugin bzip2 bzlib caps cdparanoia cdr cjk cli crypt cups curl dbus doc dri dts dvd dvdr dvdread eds emacs emboss encode esd ethereal examples exif expat fam fbcon ffmpeg flac foomaticdb fortran gcj gd gdbm gif glut gmp gnome gnutls gphoto2 gpm gstreamer gtk gtk2 gtkhtml guile hal iconv icq idn ieee1394 imagemagick imlib ipv6 isdnlog jabber jack java javascript jce jpeg junit kde kdehiddenvisibility lcms leim libg++ libgda libwww lm_sensors logrotate mad mbox mikmod milter mime mmap mmx mng motif mozilla mp3 mpeg mpi msn ncurses nls nptl nsplugin offensive ogg oggvorbis openal opengl oscar oss pam pcntl pcre pdflib perl png postgres pppd profile python qt quicktime readline recode reflection ruby sdl session sharedmem sndfile snmp sockets sox speex spell spl sse sse2 ssl svg sysvipc tcltk tcpd tetex theora threads tiff truetype truetype-fonts type1-fonts udev unicode usb v4l vhosts vorbis win32codecs wmf wxwindows xface xine xml xml2 xmms xorg xv xvid yahoo zlib elibc_glibc input_devices_keyboard input_devices_mouse kernel_linux linguas_en_GB userland_GNU video_cards_radeon video_cards_vesa video_cards_fbdev" Unset: CTARGET, EMERGE_DEFAULT_OPTS, INSTALL_MASK, LDFLAGS, PORTAGE_RSYNC_EXTRA_OPTS
have tested over and over and all is fine