Ok, so I am missing a lot of items in my NEI. It is turned on and I can search for some stuff. I am running Tekkit on MC 1.2.5. There's a lot missing, so I can't list it all, but here are some missing items: all forcefield parts, reinforced glass and stone, but not door, macerator, any chests,and furnac, all ores minus iridium and uranium... etc.
It's the same in NEI Global and World options. Single or mutiplayer.
At full screen I only have 6 pages of items.