libc upgrade breaks everything

The upgrade of the libc6 package in hardy has segfaulted and now the system is unusable. A lot of programs seg-fault, including apt/dpkg!!!

The dpkg-log is:
2008-03-13 13:33:50 upgrade libc6-amd64 2.7-5ubuntu2 2.7-9ubuntu1
2008-03-13 13:33:50 status half-configured libc6-amd64 2.7-5ubuntu2
2008-03-13 13:33:50 status unpacked libc6-amd64 2.7-5ubuntu2
2008-03-13 13:33:50 status half-installed libc6-amd64 2.7-5ubuntu2
2008-03-13 13:33:52 status half-installed libc6-amd64 2.7-5ubuntu2
2008-03-13 13:33:52 status unpacked libc6-amd64 2.7-9ubuntu1
2008-03-13 13:33:54 status unpacked libc6-amd64 2.7-9ubuntu1
2008-03-13 13:33:54 upgrade libc6 2.7-5ubuntu2 2.7-9ubuntu1
2008-03-13 13:33:54 status half-configured libc6 2.7-5ubuntu2
2008-03-13 13:33:54 status unpacked libc6 2.7-5ubuntu2
2008-03-13 13:33:54 status half-installed libc6 2.7-5ubuntu2
2008-03-13 13:33:58 status half-installed libc6 2.7-5ubuntu2
2008-03-13 13:33:58 status unpacked libc6 2.7-9ubuntu1
2008-03-13 13:34:00 status unpacked libc6 2.7-9ubuntu1
2008-03-13 13:34:00 startup packages configure
2008-03-13 13:34:00 configure libc6 2.7-9ubuntu1 2.7-9ubuntu1
2008-03-13 13:34:00 status unpacked libc6 2.7-9ubuntu1
2008-03-13 13:34:00 status unpacked libc6 2.7-9ubuntu1
2008-03-13 13:34:00 status unpacked libc6 2.7-9ubuntu1
2008-03-13 13:34:00 status unpacked libc6 2.7-9ubuntu1
2008-03-13 13:34:01 status unpacked libc6 2.7-9ubuntu1
2008-03-13 13:34:01 status unpacked libc6 2.7-9ubuntu1
2008-03-13 13:34:01 status half-configured libc6 2.7-9ubuntu1
2008-03-13 13:34:09 startup packages configure
2008-03-13 13:34:09 configure libc6 2.7-9ubuntu1 2.7-9ubuntu1
2008-03-13 13:34:09 status half-configured libc6 2.7-9ubuntu1

If I try to execute dpkg to reinstall the libc package:
$ sudo dpkg -i /var/cache/apt/archives/libc6_2.7-9ubuntu1_i386.deb
*** glibc detected *** sudo: free(): invalid pointer: 0xb7ca6b28 ***
======= Backtrace: =========
/lib/libc.so.6[0xb7e48a87]
/lib/libc.so.6(cfree+0x89)[0xb7e4a749]
/lib/libc.so.6[0xb7eda740]
/lib/libc.so.6(__libc_dlsym+0x36)[0xb7eda7c6]
/lib/libc.so.6(__nss_lookup_function+0x154)[0xb7eb5704]
/lib/libc.so.6[0xb7e8ef69]
/lib/libc.so.6(getaddrinfo+0x1a0)[0xb7e905d0]
sudo[0x804ef45]
sudo[0x8050000]
/lib/libc.so.6(__libc_start_main+0xe0)[0xb7df73a0]
sudo[0x804a521]
======= Memory map: ========
08048000-08062000 r-xp 00000000 08:05 4194533 /usr/bin/sudo
08062000-08063000 rw-p 00019000 08:05 4194533 /usr/bin/sudo
08063000-08087000 rw-p 08063000 00:00 0 [heap]
b7c6f000-b7c79000 r-xp 00000000 08:05 46137623 /lib/libgcc_s.so.1
b7c79000-b7c7a000 rw-p 0000a000 08:05 46137623 /lib/libgcc_s.so.1
b7c7a000-b7c83000 r-xp 00000000 08:05 46166457 /lib/libnss_files-2.7.so
b7c83000-b7c85000 rw-p 00008000 08:05 46166457 /lib/libnss_files-2.7.so
b7c85000-b7c8d000 r-xp 00000000 08:05 46166459 /lib/libnss_nis-2.7.so
b7c8d000-b7c8f000 rw-p 00007000 08:05 46166459 /lib/libnss_nis-2.7.so
b7c8f000-b7ca2000 r-xp 00000000 08:05 46166454 /lib/libnsl-2.7.so
b7ca2000-b7ca4000 rw-p 00012000 08:05 46166454 /lib/libnsl-2.7.so
b7ca4000-b7ca7000 rw-p b7ca4000 00:00 0
b7ca7000-b7cad000 r-xp 00000000 08:05 46166455 /lib/libnss_compat-2.7.so
b7cad000-b7caf000 rw-p 00005000 08:05 46166455 /lib/libnss_compat-2.7.so
b7cbe000-b7cfd000 r--p 00000000 08:05 50332038 /usr/lib/locale/en_US.utf8/LC_CTYPE
b7cfd000-b7cfe000 r--p 00000000 08:05 54656537 /usr/lib/locale/en_US.utf8/LC_NUMERIC
b7cfe000-b7cff000 r--p 00000000 08:05 29411206 /usr/lib/locale/en_US.utf8/LC_TIME
b7cff000-b7de0000 r--p 00000000 08:05 50432672 /usr/lib/locale/en_US.utf8/LC_COLLATE
b7de0000-b7de1000 rw-p b7de0000 00:00 0
b7de1000-b7f14000 r-xp 00000000 08:05 46166448 /lib/libc-2.7.so
b7f14000-b7f15000 r--p 00133000 08:05 46166448 /lib/libc-2.7.so
b7f15000-b7f17000 rw-p 00134000 08:05 46166448 /lib/libc-2.7.so
b7f17000-b7f1b000 rw-p b7f17000 00:00 0
b7f1b000-b7f1d000 r-xp 00000000 08:05 46166451 /lib/libdl-2.7.so
b7f1d000-b7f1f000 rw-p 00001000 08:05 46166451 /lib/libdl-2.7.so
b7f1f000-b7f28000 r-xp 00000000 08:05 46214124 /lib/libpam.so.0.81.6
b7f28000-b7f29000 rw-p 00008000 08:05 46214124 /lib/libpam.so.0.81.6
b7f29000-b7f2a000 r--p 00000000 08:05 29411207 /usr/lib/locale/en_US.utf8/LC_MONETARY
b7f2a000-b7f2b000 r--p 00000000 08:05 17335083 /usr/lib/locale/en_US.utf8/LC_MESSAGES/SYS_LC_MESSAGES
b7f2b000-b7f2c000 r--p 00000000 08:05 58779672 /usr/lib/locale/en_US.utf8/LC_PAPER
b7f2c000-b7f2d000 r--p 00000000 08:05 34710 /usr/lib/locale/en_US.utf8/LC_NAME
b7f2d000-b7f2e000 r--p 00000000 08:05 29411208 /usr/lib/locale/en_US.utf8/LC_ADDRESS
b7f2e000-b7f2f000 r--p 00000000 08:05 29411209 /usr/lib/locale/en_US.utf8/LC_TELEPHONE
b7f2f000-b7f30000 r--p 00000000 08:05 33666313 /usr/lib/locale/en_US.utf8/LC_MEASUREMENT
b7f30000-b7f37000 r--s 00000000 08:05 46179909 /usr/lib/gconv/gconv-modules.cache
b7f37000-b7f38000 r--p 00000000 08:05 29411210 /usr/lib/locale/en_US.utf8/LC_IDENTIFICATION
b7f38000-b7f39000 rw-p b7f38000 00:00 0
b7f39000-b7f3a000 r-xp b7f39000 00:00 0 [vdso]
b7f3a000-b7f54000 r-xp 00000000 08:05 46166445 /lib/ld-2.7.so
b7f54000-b7f55000 r--p 00019000 08:05 46166445 /lib/ld-2.7.so
b7f55000-b7f56000 rw-p 0001a000 08:05 46166445 /lib/ld-2.7.so
bf984000-bf999000 rw-p bffeb000 00:00 0 [stack]
Aborted

Any clue on how to recover the system? Running programs are ok, but new started programs always crash.

This bug could cause lot of problems to everybody.