How do I install iOS 3 on my 1st gen iPod touch if I've already purchased it?

I purchased an iPod touch 1st gen with 2.2.1 on it and want to update it to iOS 3. I go to the article that links me to the iTunes page to do so but instead of letting me download it, it just says it's going to download it but nothing happens. How do I get the computer to make the iPod get an update?

I'm using the link in this article to open iTunes: http://support.apple.com/kb/HT2052

This is the link I am using: https://buy.itunes.apple.com/WebObjects/MZFinance.woa/wa/touchLegacyLandingPage

when i go here it tells me I've already purchased it and just need to download it again.

I choose "download" and it says it will take about 30 minuetes but no download begins in either iTunes or in the download tray in the dock of my mac.

I let it sit for hours, and still nothing happens . . .

getting frustrated, can't find anyone else with the same problem either . . . what am I doing wrong?