Not sure what's going on but its taking for hours and hours to update itunes . last night it took nearly 3 hours to update Itunes and just plunged ipod in and its saying it will take 5 -6 hours to download iso 4! is this normal. also its stopped downloading 3 times already with error.

No it's not normal, sounds like your downloading the update on a fax modem. Do a speedtest on your internet.