rpm install failing due to dependencies

Hello Everyone

Forgive me if this has been answered already, but my eyes are going 
buggy from looking for a solution. But here it goes:

I have created a rpm for python2.5 that I want to install on a bunch of 
machines running CentOS 4. Since CentOS 4 needs python 2.3 to survive, I 
create the rpm with altinstall which doesn't make the link 
/usr/bin/python2.5 to /usr/bin/python, so everything still works. If I 
install the rpm via rpm, it works and all is happy. If I put it into a 
repo and try to install it via yum, it fails with dependency issues, 
even though python2.5 installs into it's own directory and can live with 
python2.3. How can I change this? Any help will be appreciated.

Thanks
marros