dpkg: error processing /var/cache/apt/archives/mysql-client-5.1_5.1.63-0ubuntu0.11.04.1_amd64.deb (--unpack):
 trying to overwrite '/usr/bin/perror', which is also in package mysql-server-5.1 5.1.61-0ubuntu0.10.10.1
dpkg-deb: error: subprocess paste was killed by signal (Broken pipe)
Errors were encountered while processing:
 /var/cache/apt/archives/mysql-client-5.1_5.1.63-0ubuntu0.11.04.1_amd64.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)