Tabbing to a portlet automatically pushes focus to the first tabable item inside of it.
Steps to reproduce:
1) Open the uPortal example from the daily build site:
2) Tap the tab key. Notice that when a portlet gets focus, it automatically changes focus to the first tabable item it contains.
In the case of the locked portlet, it pushes the focus to the first tabable item in the lightbox portlet.