Under Debian Squeeze I ran the command
dpkg -i bash_4.1-3+deb6u1_amd64.deb
and got the following error message:
dpkg: status database area is locked by another process

Solution:
1 – make sure you are not already runnning any package administration program in another bash session like with dpkg or apt-get or aptitude
2 – If no other package management program is concurrently running then delete the lock file with the following command:
rm /var/lib/dpkg/lock
You will then again be able to use package administration programs.