Y Can't I Install 4.3.5 on my 3G?

[Eager Beaver]

I cannot restore my 3G to a recent backup because itunes says it has old software.
So I click on update, and it updates to 4.2.1, (not 4.3.5)
I then try and restore it to my most recent backup, and same message, old software.

I click on update again, and itunes tells me I am up to date, (even though it says 4.2.1 on both itunes and "settings" on the 3G.

Does anyone know how I can get 4.3.5 on my 3G, (hoping this will allow me to restore to my latest backup and retrieve my super important business contacts).

thanks to any suggestions

 

[PsstGreek]

Anything higher than 4.2.1 isn't supported on the 3G.

 

[Eager Beaver]

Anything higher than 4.2.1 isn't supported on the 3G.

Thanks, do u have any ideas on how to retrieve my business contacts?