Ok since IP works do the following. Edit /etc/modprobe.conf and add the line.
alias ipv6 off
Next open firefox and on the browser line enter.
Then search for this line and set it from false to true.
Do the modprobe.conf first and reboot. See if you can get on then. The only reason I say this is beacuse I don't know Opera and if there is anything like that in it like the Firefox config change. Last thing is edit /etc/resolv.conf and place your ISPs DNS values in there before the the existing one. You should be able to get that info from the routers config page and see what it is using on the external wan connection.
Distribution: RHEL 5.1 with Pieces of this and that.
Kernel 220.127.116.11, KDE 3.5.8 and KDE 4.0 beta, Plus Development src.rpm, ATI fglrx64_7_1_0-8.433-1 rpm with 3D and DRI working.
Acer 5100-5840 with webcam, ati, sdcard reader, sound, atheros based wireless, all working. Only thing not working is the memory stick reader.