I have a weird problem with my Fedora 9...

Each night, when I try to log to my.yahoo.com, www.facebook.com,
www.godaddy.com, etc I cant get firefox to open the sites. It just
stays "waiting for my.yahoo.com" forever... but, if I try during the
day, it just (usually) works fine!

For example, now I can ping my.yahoo.com and get a quick response, but
firefox just gets:

Connection Interrupted
The connection to the server was reset while the page was loading.
The network link was interrupted while negotiating a connection.
Please try again.

If I try with Opera, it doesn't even show an error after prompting me
for the password... and the same happens with Konqueror:

my.yahoo.com contacted. Waiting for reply

AND I KNOW THAT IN THE MORNING IT'LL WORK!

BUT If I reboot with crappy Vista right now in the same PC, I can see
all the sites!

Isn't it weird?!?!?!?

Any ideas?