This whole pressing the button shit is getting annoying.
I give Jack a lot of credit for realizing this, although I was disappointed when he gave in and hit the button. Also, it doesn't make much sense that Locke is so obsessed with entering the code when he takes it on faith that the Island is generally a good Island. If Locke had faith in the Island, why would he feel the need to enter the code?
Can the possibly really think that the fate of the world is dependent on a two-person team entering an arbitrary code every 108 minutes? And as Jack said, with only minimal information?