Upgrading packages with rpm

[John Hodges]

A quick question for you all..

The other day there was a thread on this list about firefox rpms, so I
decided I would download and install the rpm. Predictably, it told me that
firefox required desktop-files (or something similar) and libstdc++.s0.6.
The first file desktop-whatever was part of the Fedora development tree, so
I downloaded that as well, and finally grabbed libstdc++34*rpm (since I had
libstdc++.so.5 currently on my system). What surprised me is this; I tried
to upgrade the libstdc++ package using 'rpm -Uvh libstdc++34*' and it spit
out over a page worth of packages that depend upon libstdc++.so.5. The
question, then, is would a newer version of the same package not also
satisfy these dependencies? If so, why was I not able to install using -U?

Cheers,
John