errore passando ad unstable

["matteo_battistini@libero.it" <matteo_battistini@libero.it>]

oggi mi e' venuta una strana voglia e cioe' di aggiornare ad unstable ma come
faccio apt-get upgrade mi da ilseguente errore:

---------------------
[...]
  wenglish wget witalian xchat xchat-common xlibmesa3 xpdf xpdf-reader
  xpdf-utils
182 packages upgraded, 0 newly installed, 0 to remove and 78  not upgraded.
Need to get 0B/127MB of archives. After unpacking 34.2MB will be used.
Do you want to continue? [Y/n] y
Preconfiguring packages ...
(Reading database ... 40988 files and directories currently installed.)
Preparing to replace login 20000902-12 (using .../login_1%3a4.0.3-7_i386.deb) ...
Unpacking replacement login ...
dpkg: error processing /var/cache/apt/archives/login_1%3a4.0.3-7_i386.deb
(--unpack):
 trying to overwrite `/usr/share/man/it/man1/login.1.gz', which is also in
package manpages-it
dpkg-deb: subprocess paste killed by signal (Broken pipe)
Errors were encountered while processing:
 /var/cache/apt/archives/login_1%3a4.0.3-7_i386.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)
----------------
e' grave? rinuncio?

ciao
   Matteo