You could try
Code:
ps aux | grep dpkg-configure
which will list all of the running processes with dpkg-configure in the name. The second column is the process ID, which you can then try to kill.
There's also a "killall" command which kills every process with a particular name, so in your case:
Code:
killall dpkg-configure
Also, in case you didn't know, then both kill and killall accept the parameter "-9" which will force kill the relevant process(es). This should only really be used as a last resort though, as the affected process will not be given any opportunity to shut down nicely, clean up temporary files and so on.
As a final point, do you know which package caused APT and dpkg to get in this state. If it happens repeatedly for no apparent reason, it might be worth filing a bug against the package.
Hope this helps!