Broken RPM, version mismatches, and atrpms

[Philip Prindeville <philipp_subx@xxxxxxxxxxxxxxxxxxxxx>]

I naively added atrpms to my /etc/yum.repos.d/ directory, and have yum 
running
nightly.  This is on FC3.

As a consequence, the following night, yum went and grabbed a bunch of 
packages
and installed them.  I think it's destabilized my system, to the point 
that RPM won't
even run now:

[root@mail ~]# rpm -qa
rpmdb: Program version 4.3 doesn't match environment version
error: db4 error(-30974) from dbenv->open: DB_VERSION_MISMATCH: Database 
environment version mismatch
error: cannot open Packages index using db3 -  (-30974)
error: cannot open Packages database in /var/lib/rpm
[root@mail ~]#


How do I back this out and restore things to normalcy?

Thanks,

-Philip