I can reproduce this; loading planet.mozilla.org produces a SIGABRT with a very similar backtrace (full dump attached). I started experiencing frequent SIGABRT crashes after upgrading from Hardy to Intrepid.

maiken@maikendev:~$ sudo apt-cache policy firefox-3.0
firefox-3.0:
  Installed: 3.0.3+nobinonly-0ubuntu2
  Candidate: 3.0.3+nobinonly-0ubuntu2
  Version table:
 *** 3.0.3+nobinonly-0ubuntu2 0
        500 http://us.archive.ubuntu.com intrepid/main Packages
        100 /var/lib/dpkg/status
maiken@maikendev:~$ uname -a
Linux maikendev 2.6.27-7-generic #1 SMP Tue Nov 4 19:33:20 UTC 2008 i686 GNU/Linux
maiken@maikendev:~$ lsb_release -rd
Description:	Ubuntu 8.10
Release:	8.10

See also https://bugs.launchpad.net/bugs/282287 against the "firefox" package.

#1  0xb7d6b880 in raise () from /lib/tls/i686/cmov/libc.so.6
No symbol table info available.
#2  0xb7d6d248 in abort () from /lib/tls/i686/cmov/libc.so.6
No symbol table info available.
#3  0xb3a935dd in talloc_free () from /usr/lib/libtalloc.so.1
No symbol table info available.
#4  0xb0b05289 in ?? () from /lib/libnss_wins.so.2
No symbol table info available.
#5  0xb3a93621 in talloc_free () from /usr/lib/libtalloc.so.1
No symbol table info available.
#6  0xb0b30758 in alloc_sub_basic () from /lib/libnss_wins.so.2
No symbol table info available.
#7  0xb0b30d3f in talloc_sub_basic () from /lib/libnss_wins.so.2
No symbol table info available.
#8  0xb0a70281 in ?? () from /lib/libnss_wins.so.2
No symbol table info available.
#9  0xb0a713f2 in lp_lockdir () from /lib/libnss_wins.so.2
No symbol table info available.
#10 0xb0b2aa75 in lock_path () from /lib/libnss_wins.so.2
No symbol table info available.
#11 0xb0ac9767 in receive_unexpected () from /lib/libnss_wins.so.2
No symbol table info available.
#12 0xb0acc375 in receive_nmb_packet () from /lib/libnss_wins.so.2
No symbol table info available.
#13 0xb0acee4d in name_query () from /lib/libnss_wins.so.2
No symbol table info available.
#14 0xb0a6c555 in _nss_wins_gethostbyname_r () from /lib/libnss_wins.so.2
No symbol table info available.
#15 0xb0a6c853 in _nss_wins_gethostbyname2_r () from /lib/libnss_wins.so.2
No symbol table info available.
#16 0xb7e05666 in gaih_inet () from /lib/tls/i686/cmov/libc.so.6
No symbol table info available.
#17 0xb7e07039 in getaddrinfo () from /lib/tls/i686/cmov/libc.so.6
No symbol table info available.
#18 0xb7c7d6b9 in PR_GetAddrInfoByName (
    hostname=0x86b3664 "stats.wordpress.com", af=0, flags=32800)
    at prnetdb.c:2042
        res = <value optimized out>
        hints = {ai_flags = 0, ai_family = 0, ai_socktype = 1, 
  ai_protocol = 0, ai_addrlen = 0, ai_addr = 0x0, ai_canonname = 0x0, 
  ai_next = 0x0}
        rv = <value optimized out>
#19 0xb725f454 in nsHostResolver::ThreadFunc (arg=0x836a600)
    at nsHostResolver.cpp:697
        flags = 32800
        status = <value optimized out>
        rec = (nsHostRecord *) 0x86b3630
        ai = (PRAddrInfo *) 0x1
#20 0xb7c8b1e1 in _pt_root (arg=0xa1fe8b0) at ptthread.c:221
        detached = 1
#21 0xb7fcd50f in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
No symbol table info available.
#22 0xb7e217ee in clone () from /lib/tls/i686/cmov/libc.so.6
No symbol table info available.