freeze during install

[Axel <axel azerty laposte net>]

I downloaded boot iso from ftp.crihan.fr mirror and tried to make a 
fresh install of FC7. Boot goes well and installation wizard starts 
without problem.
After the dependancies computation and the / & swap format the install 
stop. No "lock", GUI can be use but the install waits with a progress 
bar which doesn'nt progress anymore.

In one of the tty I see the message "No handler could be found for 
yum.Yumbase" or something like that.

Is that a known problem for test 2 or maybe I forgot something ?

Regards
Axel