Installing multiple versions of devel/py-setuptools

[hideo]

Hi,

I'm trying get a patch for sabnzbdplus to work that restricts
the python version to <=2.5.  I have USE_PYTHON= -2.5 but
when py-setuptools gets pulled in as a dependency, the install
fails if another version has already installed it:

===>  Installing for py24-setuptools-0.6c9
===>   py24-setuptools-0.6c9 depends on file: /usr/local/bin/python2.4 - found
===>   Generating temporary packing list
===>  Checking if devel/py-setuptools already installed
===>   An older version of devel/py-setuptools is already installed (py26-setuptools-0.6c9)
      You may wish to ``make deinstall'' and install this port again
      by ``make reinstall'' to upgrade it properly.
      If you really wish to overwrite the old port of devel/py-setuptools
      without deleting it first, set the variable "FORCE_PKG_REGISTER"
      in your environment or the "make install" command line.
*** Error code 1

Stop in /usr/ports/devel/py-setuptools.
*** Error code 1

Stop in /usr/ports/devel/py-cheetah.
*** Error code 1

Stop in /yaf/hideo/stuff/ports/sabnzbdplus.
*** Error code 1

Stop in /yaf/hideo/stuff/ports/sabnzbdplus.

Is there a way around this?

Thanks,
Zach