Is it the version of Android you're running? I know that on my Dad's Telecom NZ Galaxy S he's still on 2.1 because they haven't authorised any 2.2 updates through Kies for it. I tried to install a cool synth app I'd been wanting to test on it, but because of no 2.2 update it wouldn't work.

That's android's biggest problem: carriers delaying updates for ages because of "testing". It's fine for hacky people, but for the general public like my dad who enjoy having cool new tech but CBF dealing with spoofing Kies to get it to install European updates, it's super frustrating knowing that someone else with the same phone has an improved version just because they live somewhere else.