iTunes tags not syncing with iPod

So I have an iPod touch 64gb 3rd gen. When tagging files in iTunes the corresponding tags do not appear on my iPod.

For example, 'Foo Fighters - Rope' shows only in my iPod as 'Rope' with no Artist. Even though it shows as that on the iPod list on iTunes.

This is happening for every file that isn't tagged before putting into my iTunes. I know I could use tagging software to tag these files then reload them into iTunes but A) That defeats a big point of iTunes, and B) without scrolling through every song on my iPod I have no way of remembering which of the many files will need me to do this.

There are also various other tagging issues that are messing my iPod songs info up.

I have tried fully deinstalling and reinstalling iTunes, including the iTunes library files. I have even tried to install old versions of iTunes but these fail to install with no explanation to the error.

Please help, my iPod is a jumbled mess and I need some hope!

Thanks.