I'm having a similar but possibly not identical error (I got "realloc()" where others have "double free or corruption" or "malloc()"). Since installing pango-graphite last night, the Bookmarks toolbar and parts of many webpages (e.g. Gmail, thereifixedit.com) have large inter-word spacing, and Firefox crashes within a few clicks. Firefox 3.0.14+build2+nobinonly-0ubuntu0.9.04.1 on Kubuntu Jaunty. Why do I suspect that pango-graphite is responsible? Because it's the only rendering-related change I've made since everything was normal. And sure enough, after uninstalling it (and libgraphite3, to be safe), everything looks normal again and Firefox has stayed stable at least long enough to test for crashes, browse around a bit, get to Launchpad, and post this. Here's the error info; ignore the "wrong ELF class" warnings, they're still around after uninstalling pango-graphite. ** (firefox:4843): WARNING **: Exception in gr::RangeSegment ** (firefox:4843): WARNING **: Exception in gr::RangeSegment ** (firefox:4843): WARNING **: Exception in gr::RangeSegment [...Repeat ad nauseum...] ** (firefox:4843): WARNING **: Exception in gr::RangeSegment ** (firefox:4843): WARNING **: Exception in gr::RangeSegment ** (firefox:4843): WARNING **: Exception in gr::RangeSegment ** (firefox:4843): WARNING **: Exception in gr::RangeSegment Gtk-Message: Failed to load module "canberra-gtk-module": /usr/lib/gtk-2.0/modules/libcanberra-gtk-module.so: wrong ELF class: ELFCLASS64 (npviewer.bin:4875): Gtk-WARNING **: /usr/lib/gtk-2.0/2.10.0/engines/libqtcurve.so: wrong ELF class: ELFCLASS64 *** glibc detected *** /usr/lib/firefox-3.0.14/firefox: realloc(): invalid next size: 0x0000000007ccbeb0 *** ======= Backtrace: ========= /lib/libc.so.6[0x7f3ab0087cb8] /lib/libc.so.6[0x7f3ab008bf21] /lib/libc.so.6(realloc+0x12e)[0x7f3ab008cdae] /usr/lib/libglib-2.0.so.0(g_realloc+0x2e)[0x7f3aabe7693e] /usr/lib/libpango-1.0.so.0(pango_glyph_string_set_size+0x3d)[0x7f3aaca0febd] /usr/lib/pango/1.6.0/modules/pango-basic-fc.so[0x7f3a9f94f3da] /usr/lib/libpango-1.0.so.0(pango_shape+0x4a)[0x7f3aaca26eba] /usr/lib/xulrunner-1.9.0.14/libxul.so(_ZN17gfxPangoFontGroup24CreateGlyphRunsItemizingEP10gfxTextRunPKcjj+0x1fc)[0x7f3aaef937ea] /usr/lib/xulrunner-1.9.0.14/libxul.so(_ZN17gfxPangoFontGroup11MakeTextRunEPKtjPKN17gfxTextRunFactory10ParametersEj+0x10e)[0x7f3aaef93b76] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaef8fd49] /usr/lib/xulrunner-1.9.0.14/libxul.so(_ZN15gfxTextRunCache11MakeTextRunEPKtjP12gfxFontGroupP10gfxContextjj+0x39)[0x7f3aaef8e8bb] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaeec60ea] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaeec552a] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaef7af14] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aae932830] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea23b8e] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea23beb] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea23c13] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea19dd1] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea16841] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea174d7] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea16841] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea174d7] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea16841] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea174d7] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea16841] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea174d7] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea16841] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aae96741a] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea174d7] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea16841] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea19dd1] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea16841] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea174d7] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea16841] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea174d7] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea16841] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea174d7] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea16841] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea174d7] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea16841] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea174d7] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea16841] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea174d7] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea16841] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea174d7] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea16841] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea18cd9] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea1573b] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea1505d] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea1a1c0] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea1573b] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea1505d] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaea16aa9] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aae957121] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aae99d5e8] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aae939675] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aae93cbc1] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aae93cd12] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaebbda24] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaebc28e6] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaebb400b] /usr/lib/xulrunner-1.9.0.14/libxul.so[0x7f3aaebb04a2] ======= Memory map: ======== 00400000-00408000 r-xp 00000000 08:07 53805 /usr/lib/firefox-3.0.14/firefox 00608000-00609000 r--p 00008000 08:07 53805 /usr/lib/firefox-3.0.14/firefox 00609000-0060a000 rw-p 00009000 08:07 53805 /usr/lib/firefox-3.0.14/firefox 00b51000-0b71a000 rw-p 00b51000 00:00 0 [heap] 7f3a94927000-7f3a94928000 ---p 7f3a94927000 00:00 0 7f3a94928000-7f3a95128000 rw-p 7f3a94928000 00:00 0 7f3a95128000-7f3a95129000 ---p 7f3a95128000 00:00 0 7f3a95129000-7f3a95929000 rw-p 7f3a95129000 00:00 0 7f3a95929000-7f3a9592e000 r-xp 00000000 08:02 8657 /lib/libnss_dns-2.9.so 7f3a9592e000-7f3a95b2d000 ---p 00005000 08:02 8657 /lib/libnss_dns-2.9.so 7f3a95b2d000-7f3a95b2e000 r--p 00004000 08:02 8657 /lib/libnss_dns-2.9.so 7f3a95b2e000-7f3a95b2f000 rw-p 00005000 08:02 8657 /lib/libnss_dns-2.9.so 7f3a95b2f000-7f3a95b31000 r-xp 00000000 08:02 2434 /lib/libnss_mdns4_minimal.so.2 7f3a95b31000-7f3a95d30000 ---p 00002000 08:02 2434 /lib/libnss_mdns4_minimal.so.2 7f3a95d30000-7f3a95d31000 rw-p 00001000 08:02 2434 /lib/libnss_mdns4_minimal.so.2 7f3a95d31000-7f3a95d32000 ---p 7f3a95d31000 00:00 0 7f3a95d32000-7f3a96532000 rw-p 7f3a95d32000 00:00 0 7f3a96532000-7f3a96533000 ---p 7f3a96532000 00:00 0 7f3a96533000-7f3a96d33000 rw-p 7f3a96533000 00:00 0 7f3a96db3000-7f3a96db4000 ---p 7f3a96db3000 00:00 0 7f3a96db4000-7f3a975b4000 rw-p 7f3a96db4000 00:00 0 7f3a975b4000-7f3a97616000 r-xp 00000000 08:07 25480 /usr/lib/nss/libnssckbi.so 7f3a97616000-7f3a97816000 ---p 00062000 08:07 25480 /usr/lib/nss/libnssckbi.so 7f3a97816000-7f3a97825000 r--p 00062000 08:07 25480 /usr/lib/nss/libnssckbi.so 7f3a97825000-7f3a9782e000 rw-p 00071000 08:07 25480 /usr/lib/nss/libnssckbi.so 7f3a9782e000-7f3a9788f000 r-xp 00000000 08:07 13857 /usr/lib/nss/libfreebl3.so 7f3a9788f000-7f3a97a8f000 ---p 00061000 08:07 13857 /usr/lib/nss/libfreebl3.so 7f3a97a8f000-7f3a97a90000 r--p 00061000 08:07 13857 /usr/lib/nss/libfreebl3.so 7f3a97a90000-7f3a97a91000 rw-p 00062000 08:07 13857 /usr/lib/nss/libfreebl3.so 7f3a97a91000-7f3a97a95000 rw-p 7f3a97a91000 00:00 0 7f3a97a95000-7f3a97abd000 r-xp 00000000 08:07 25479 /usr/lib/nss/libnssdbm3.so 7f3a97abd000-7f3a97cbd000 ---p 00028000 08:07 25479 /usr/lib/nss/libnssdbm3.so 7f3a97cbd000-7f3a97cbe000 r--p 00028000 08:07 25479 /usr/lib/nss/libnssdbm3.so 7f3a97cbe000-7f3a97cbf000 rw-p 00029000 08:07 25479 /usr/lib/nss/libnssdbm3.so 7f3a97cbf000-7f3a97cfd000 r-xp 00000000 08:07 25478 /usr/lib/nss/libsoftokn3.so 7f3a97cfd000-7f3a97efc000 ---p 0003e000 08:07 25478 /usr/lib/nss/libsoftokn3.so 7f3a97efc000-7f3a97efe000 r--p 0003d000 08:07 25478 /usr/lib/nss/libsoftokn3.so 7f3a97efe000-7f3a97eff000 rw-p 0003f000 08:07 25478 /usr/lib/nss/libsoftokn3.so 7f3a97f68000-7f3a98000000 r--p 00000000 08:07 35363 /usr/share/fonts/truetype/ttf-dejavu/DejaVuSans.ttf 7f3a98000000-7f3a98361000 rw-p 7f3a98000000 00:00 0 7f3a98361000-7f3a9c000000 ---p 7f3a98361000 00:00 0 7f3a9c021000-7f3a9c065000 r--p 00000000 08:07 125573 /usr/share/fonts/truetype/msttcorefonts/Arial.ttf 7f3a9c065000-7f3a9c0fe000 r-xp 00000000 08:07 3633 /usr/lib/libsmbios.so.2.1.0 7f3a9c0fe000-7f3a9c2fd000 ---p 00099000 08:07 3633 /usr/lib/libsmbios.so.2.1.0 7f3a9c2fd000-7f3a9c305000 r--p 00098000 08:07 3633 /usr/lib/libsmbios.so.2.1.0 7f3a9c305000-7f3a9c306000 rw-p 000a0000 08:07 3633 /usr/lib/libsmbios.so.2.1.0 7f3a9c306000-7f3a9c316000 r-xp 00000000 08:07 655 /usr/lib/libhal.so.1.0.0 7f3a9c316000-7f3a9c515000 ---p 00010000 08:07 655 /usr/lib/libhal.so.1.0.0 7f3a9c515000-7f3a9c516000 r--p 0000f000 08:07 655 /usr/lib/libhal.so.1.0.0 7f3a9c516000-7f3a9c517000 rw-p 00010000 08:07 655 /usr/lib/libhal.so.1.0.0 7f3a9c517000-7f3a9c5dc000 r-xp 00000000 08:07 125188 /usr/lib/libvlccore.so.0.1.0 7f3a9c5dc000-7f3a9c7dc000 ---p 000c5000 08:07 125188 /usr/lib/libvlccore.so.0.1.0 7f3a9c7dc000-7f3a9c7e1000 r--p 000c5000 08:07 125188 /usr/lib/libvlccore.so.0.1.0 7f3a9c7e1000-7f3a9c7e4000 rw-p 000ca000 08:07 125188 /usr/lib/libvlccore.so.0.1.0 7f3a9c7e4000-7f3a9c7f5000 r-xp 00000000 08:07 2653 /usr/lib/libXpm.so.4.11.0 7f3a9c7f5000-7f3a9c9f4000 ---p 00011000 08:07 2653 /usr/lib/libXpm.so.4.11.0 7f3a9c9f4000-7f3a9c9f5000 rw-p 00010000 0Killed