The Small Wave.

Mr. Papermaster had lost the confidence of Mr. Jobs months ago and hasn't been part of the decision-making process for some time, these people said. They added that Mr. Papermaster didn't appear to have the type of creative thinking expected at Apple and wasn't used to Apple's corporate culture, where even senior executives are expected to keep on top of the smallest details of their areas of responsibility and often have to handle many tasks directly, as opposed to delegating them.

Makes sense that Big Blue's and Apple's corporate culture differences would be a quite a shock. The article also states it was Jobs who green-lighted going ahead with the iPhone 4.