iTunes "clicking" buttons twice when clicked on

I've been having a strange problem with iTunes ever since I installed Leopard. If the iTunes mini window is in the background (iTunes is not the frontmost/active application), and I click on the Play, Next or Previous buttons, iTunes registers it as clicking twice. For example, if a song is playing and I hit the pause button when the mini window is in the background, it will quickly change to the play button and stop the music, then a millisecond later, will start playing the song again and change the button to a pause button. If I hit the next button, it goes forward 2 songs, not 1. I am not clicking twice, even on accident. It happens with my mouse and trackpad button. I am using iTunes 7.6.2 and OS X 10.5.3, but have had this issue since 10.5 and whatever version of iTunes was available then. I know many people have this problem, but no one knows of a fix.

While we are on the subject of iTunes, another problem I'm having (I had this in 10.4 and 10.5) is that iTunes will randomly stop in the middle of songs. It is not reproducible, and doesn't happen twice on the same song or in the same spot, which I think means that the music is fine (not corrupted). If I click play, it starts playing again.

I don't have any third party iTunes software on my Mac.

Any ideas? This is very irritating and Apple doesn't fix it!