[CentOS] packages downgraded when going from 5.0 to 5.1

Thu Dec 6 16:06:53 UTC 2007
Nicolas Thierry-Mieg <Nicolas.Thierry-Mieg at imag.fr>

Hello,

I have a few packages where the latest updated version in 5.0 is greater 
than the current 5.1 version.

Here is the list: package, installed version (from 5.0 updates), 
available (in 5.1)

flac
1.1.2-28.el5_0.1
1.1.2-27

flac-devel
1.1.2-28.el5_0.1
1.1.2-27

hpijs
1.6.7-4.1.el5.3
1.6.7-4.1

libsane-hpaio
1.6.7-4.1.el5.3
1.6.7-4.1

thunderbird
1.5.0.12-5.el5.centos
1.5.0.12-3.el5.centos


I use mirrors.ircam.fr, and apt+synaptic but I don't think that's the 
reason (except perhaps for the hp stuff?)

Is something wrong on my side? If not, should I downgrade those packages 
to the 5.1 versions?

Thanks in advance


cheers,
Nicolas