The official name for ATA33, 66, etc is Ultra Direct Memory Acces (UDMA) 3, 4, 5... they are also called Ultra ATA66 and higher. So Ultra or non-Ultra cables should be the same. It could be that Ultra cables (if frome the same manufactuer) are shielded but that doesn't matter with the default 18" cables.
My PC eats so much money that I'm in 'desperate' need of it to buy PC3500 RAM, help Svol with his OC project!
--- PM me for information.