Problems Upgrading to Edgy

[Robert Tilley]

The following error occurred during my attempted upgrade, via aptitude, to 
Edgy Eft from Dapper Drake.

tilleyrw at tilleyrw-desktop:~/downloads$ sudo aptitude
Extracting templates from packages: 100%
Preconfiguring packages ...
(Reading database ... 187747 files and directories currently installed.)
Preparing to replace libarts1-audiofile 4:3.5.5-0ubuntu1~dapper1 
(using .../libarts1-audiofile_4%3a3.5.6-0ubuntu1~edgy1_i386.deb) ...
Unpacking replacement libarts1-audiofile ...
dpkg: error 
processing /var/cache/apt/archives/libarts1-audiofile_4%3a3.5.6-0ubuntu1~edgy1_i386.deb 
(--unpack):
 trying to overwrite `/usr/lib/libarts_audiofile.so', which is also in package 
kdemultimedia-dev
Errors were encountered while processing:
 /var/cache/apt/archives/libarts1-audiofile_4%3a3.5.6-0ubuntu1~edgy1_i386.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)
A package failed to install.  Trying to recover:
Press return to continue.

I've tried deleting the file `/usr/lib/libarts_audiofile.so' (so it _can't_ be 
overwritten) to solve this problem.  Does anyone have any further ideas?

Thanks, Bob

P.S.  Should I just download the official Edgy CD and use it for a re-install?