Have I misread something's or is it me:

I have installed iTunes version 8, in all the Preferences ringtones are selected but the option does not appear in the music menu.

I have looked at the Mac & iTunes help pages and they suggest the screen resolution might be wrong, but is set at 1680 x 1050 which should be ok.
Can anyone please suggest what I might try to create a ringtone for my iPhone.

I am using a Mac Book Pro, iPhone 3G (Version 2.1) with iTunes version 8.

Many thanks,