package ecm 1.00-0ubuntu2 failed to install/upgrade: trying to overwrite '/usr/bin/ecm', which is also in package gmp-ecm 0:6.2-1

Binary package hint: ecm

gmp-ecm and ecm are both packages in Universe. The first is a math program and the second one deals with a format for cdrom images. Apparently they both call their command ecm. These are the involved versions:

$ apt-cache policy gmp-ecm
gmp-ecm:
  Installed: 6.2-1
  Candidate: 6.2-1
  Version table:
 *** 6.2-1 0
        500 http://us.archive.ubuntu.com karmic/universe Packages
        100 /var/lib/dpkg/status
That is what I had installed when I tried to install ecm (and it failed). This is the ecm package:

$ apt-cache policy ecm
ecm:
  Installed: 1.00-0ubuntu2
  Candidate: 1.00-0ubuntu2
  Version table:
 *** 1.00-0ubuntu2 0
        500 http://us.archive.ubuntu.com karmic/universe Packages
        100 /var/lib/dpkg/status
$

If I had had ecm installed and tried to install gmp-ecm it would have been the same problem, obviously so the problem really affects both packages.

ProblemType: Package
AptOrdering:
 ecm: Install
 ecm: Configure
Architecture: amd64
Date: Sun Sep 26 17:33:28 2010
DistroRelease: Ubuntu 9.10
ErrorMessage: trying to overwrite '/usr/bin/ecm', which is also in package gmp-ecm 0:6.2-1
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release amd64 (20091027)
NonfreeKernelModules: nvidia
Package: ecm 1.00-0ubuntu2
ProcVersionSignature: Ubuntu 2.6.31-22.65-server
SourcePackage: ecm
Title: package ecm 1.00-0ubuntu2 failed to install/upgrade: trying to overwrite '/usr/bin/ecm', which is also in package gmp-ecm 0:6.2-1
Uname: Linux 2.6.31-22-server x86_64