Thanks Mylenium, I truly appreciate your response and time/energy.
I did allow noscript to pass, and it was a brand new installation from Sun Java and brand new install of Firefox, was in fact why I installed both specifically for the trial because it wasn't working in Opera or IE. =/ Hence is why i think it's Vista related or server side.
I will try looking closer at Java related issues again like you suggest, another browser or try it from another computer. Hopefully post an update if I figure it out lol.
Take a look here: http://kb2.adobe.com/cps/402/kb402065.html
I have succesfully downloaded the trial on Vista. But there are a bunch of things you have to say yes to (including having the JRE installed).
It's a little bit of a pain to setup, but due to the size of the After Effects trial installer, you'll get better download speeds, and the ability to restart if the download is interrupted.