snippet.txt

Selecting previously deselected package mysql-client-5.1.
(Reading database ... 92733 files and directories currently installed.)
Unpacking mysql-client-5.1 (from .../mysql-client-5.1_5.1.58-1~dotdeb.1_i386.deb) ...
Selecting previously deselected package mysql-server-core-5.1.
Unpacking mysql-server-core-5.1 (from .../mysql-server-core-5.1_5.1.58-1~dotdeb.1_i386.deb) ...
Unpacking mysql-server-5.1 (from .../mysql-server-5.1_5.1.58-1~dotdeb.1_i386.deb) ...
Aborting downgrade from (at least) 5.5 to 5.1.
If are sure you want to downgrade to 5.1, remove the file
/var/lib/mysql/debian-*.flag and try installing again.
dpkg: error processing /var/cache/apt/archives/mysql-server-5.1_5.1.58-1~dotdeb.1_i386.deb (--unpack):
 subprocess new pre-installation script returned error exit status 1
Processing triggers for man-db ...
Errors were encountered while processing:
 /var/cache/apt/archives/mysql-server-5.1_5.1.58-1~dotdeb.1_i386.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)