problema con dist-upgrade

[agenteo <outerheaven.liste@tiscali.it>]

ciao,
ho installato debian woody base, con in più i pacchetti mc less e vim.
Poi ho inserito i mirror per l'upgrade ad unstable e ho dato apt-get
update e apt-get dist-upgrade -u sembrava che tutto procedesse bene
quando ho ricevuto degli errori su dei pacchetti.
Quando ho ridato apt-get upgrade vedevo:
Reading Package Lists... Done
Building Dependency Tree... Done
Calculating Upgrade... Done
The following packages have been kept back:
  mc
0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.
4 not fully installed or removed.
Need to get 0B of archives.
After unpacking 0B of additional disk space will be used.
Do you want to continue? [Y/n] y
Setting up cron (3.0pl1-84) ...
chgrp: cannot access `/usr/bin/crontab': No such file or directory
dpkg: error processing cron (--configure):
 subprocess post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of logrotate:
 logrotate depends on cron (>= 3.0pl1-53) | anacron; however:
  Package cron is not configured yet.
  Package anacron is not installed.
dpkg: error processing logrotate (--configure):
 dependency problems - leaving unconfigured
dpkg: dependency problems prevent configuration of exim:
 exim depends on cron (>= 3.0pl1-42); however:
  Package cron is not configured yet.
dpkg: error processing exim (--configure):
 dependency problems - leaving unconfigured
dpkg: dependency problems prevent configuration of mailx:
 mailx depends on exim4 | mail-transport-agent; however:
  Package exim4 is not installed.
  Package mail-transport-agent is not installed.
  Package exim which provides mail-transport-agent is not configured
yet.
dpkg: error processing mailx (--configure):
 dependency problems - leaving unconfigured
Errors were encountered while processing:
 cron
 logrotate
 exim
 mailx
E: Sub-process /usr/bin/dpkg returned an error code (1)
così ho installato manualmente mc. Fatto questo quando ridavo apt-get
upgrade non vedevo più il messaggio: "The following packages have been
kept back:" ma che 4 pacchetti non erano correttamente installati. Ho
lanciato dselect e ho scelto l'opzione per riparare i pacchetti ma non è
cambiato niente. Alla fine ho rimosso cron e lo ho reinstallato (creando
manualmente un file /usr/bin/crontab). Adesso apt-get upgrade e apt-get
dist-upgrade non aggiornano nulla ma non sò se il passaggio ad unstable
è andato a buon fine!
Mi potreste dare qualche indicazione?
Grazie,
Enrico