... and because some package is provided in the MAIN repository
does not mean its stable, either. I run amanda and have been doing
since 1998, the version that is in the main repository (2.5.0p2)
is 5 years old and crashed my 5.4 server (and another server I
look after part time voluntarily). I currently run a self compiled
2.6.1 and never looked back (this includes all of amanda's clients).

 
I don't think you understand how Red Hat (and thus CentOS) package
things.

The version of Amanda in RHEL 5.4 and CentOS 5.4 is indeed
2.5.0p2-8 (the -8 is important) and is not yet 6 months old, much
less 5 years old. When Red Hat packages RPMs, they often times
back port security patches and bugfixes.

As to why it crashed you server,  I can bet that there are other config
and software changes you have added "by hand" that may have caused
a problem. We have a few CentOS 5.4 systems running the standard
amanda packages without any problems.

Ian