crm:~# aptitude install mysql-server-5.1
The following NEW packages will be installed:
  mysql-client-5.1{ab} mysql-server-5.1{b} mysql-server-core-5.1{ab}
0 packages upgraded, 3 newly installed, 0 to remove and 12 not upgraded.
Need to get 20.0 MB of archives. After unpacking 47.1 MB will be used.
The following packages have unmet dependencies:
  mysql-server-5.1: Conflicts: mysql-server (< 5.1.63-0+squeeze1) but 5.0.51a-24+lenny5 is installed and it is kept back.
  mysql-client-5.1: Conflicts: mysql-client-5.0 but 5.0.51a-24+lenny5 is installed.
  mysql-server-core-5.1: Conflicts: mysql-server-5.0 (< 5.1.45-2) but 5.0.51a-24+lenny5 is installed.
The following actions will resolve these dependencies:

     Remove the following packages:
1)     mysql-client-5.0
2)     mysql-server
3)     mysql-server-5.0



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