cant get out with anything other than firefox

["dsc21b people net au" <dsc21b people net au>]

hi all
the internet connection is working fine - firefox and other computers access the internet ok, on all levels.
firefox is working fine, web mail is all i can use
thunderbird/evolution/irc/yum/up2date cant access the net
with selinux turned off
with the firewall turned off
no going out
loaded of dvd = the same
loaded of cd´s = the same
on two different machines
any ideas would be good please
nothing is blocked anywhere
this was awroking fedora 5, 60 minutes ago
thanks
david