F17 - yum does not update!

[Cristian Sava]

Hi all,

I installed F17 x64 in a virtual box and resulted F17 fully updated and
works well.
But when trying to install any new package ...
>yum install iptraf
....
iptraf-ng-1.1.1-1.fc17.x86_64. FAILED curl#7 - "Couldn't connect"
....
Trying other mirror.
and so on!

Same as
http://lists.fedoraproject.org/pipermail/users/2012-November/427243.html

Modifying in yum.repos.d does not help.
Same install with Centos 6.3 x64 with same result!

Why this, what's wrong now? Any sugestion?

Thanks

C. Sava