Yum can't find anything !

[Leandro Melo]

Hi.
I haven't used my fc2 for a few months (maybe 3).
So, when I typed "yum list available" this morning, I got a lot of
error and didn't get any package's output. If I try to search for some
package (even if I search for something like *dev* what would probably
give a few results) I can't find anything either (and also get those
errors).
What could be the reason of this problem?
Thanks.
-- 
Leandro