Open Radar

 
Summary:
When scrolling a long list in iTunes with a Magic Mouse (sidebar, browse panels, or music list), care must be taken to ensure that the mouse cursor does not move from that frame until the scrolling motion has fully stopped. Otherwise, the scroll will continue, but in the new navigation area.

Steps to Reproduce:
1) Open iTunes 10.0 or newer with a large (10,000+ songs) library. The large library makes this behaviour more apparent.
2) Set it up so that the Browse panels are located at the top of the Hybrid List view.
3) Begin scrolling the Genre browse panel with inertial-style scrolling. That is to say a quick flick on the top of the Mighty Mouse shell.
4) While the scrolling is slowing down in the Genre panel, move the cursor to the Artists panel.

Expected Results:
The Genre panel should complete its scroll, but the Artist panel should not receive the same action as the scroll was not directed to the Artist panel.

Actual Results:
The list of Artists begins to scroll.

Regression:
This appears to occur with only a Magic Mouse, though I have not tried it with a Magic Trackpad. It does not occur with a mouse with a scroll wheel or a scroll ball, as neither possess inertial scrolling capabilities.

Notes:
[Video attached to Apple bug report, but not here]