Can't update iPhone 3GS to 4.3.3
iTunes prompts me to download and update my iPhone, I choose to do so. When it's completed downloading and stuff, it says that my iPhone isn't eligible for the requested build.
This seems odd, I've had this problem before and I fixed it by updating iTunes, this time iTunes is already up to date.
Also, if it truly isn't eligible then it shouldn't prompt me to update it. The device compatibility list in the update info thingy says that the iPhone 3GS is compatible.
Suggestions?
iPhone 3GS, iOS 4.3.2