dist-upgrade from stable to testing

[Phil Reardon <pcreard@home.com>]

After apt-get update, apt-get dist-upgrade to testing, I got a successful 
download of 166 MB. But during the install/config, I saw this message:

mv: cannot create regjular file '/etc/exim/exim.conf' ;  No such file or 
directory.  

dpkg: error processing /var/cach/apt/archives/exim_3.31-1_i386.deb 
(--unpack); subprocess pre-installaation script returned error exit status 1
 Starting MTA exim

This was followed by several lines that look okay and then by

Errors were encountered while processing: 
/var/cache/apt/archives/exim_3.31-1_i386.deb
E: Subprocess /usr/bin/dpkg returned an error code (1)

This was followed by my root prompt.  I checked, and exim.conf is directly 
under /etc, and I have no exim directory under /etc, which I presume was the 
problem.  My question is , what should I do next?  Do I have to repeat the 
dist-upgrade, or even do something worse?  The box I did this on is waiting 
for your gracious help!