I ran into a problem while installing the iPhone SDK. A few minutes from the end the install paused and I was prompted with an “Installation Alert” informing me that iTunes needed to be closed before the install could proceed.
I closed iTunes but the prompt remained. Well, the install process had taken a long time so I didn’t want to quit and start over. The solution was simple.
I opened “Activity Monitor” and noticed that while iTunes wasn’t open the “iTunes Helper” process was still active. I shut down the process and a few seconds later the install of the SDK proceeded.