[macosx] Pressing Up / Down arrow on a List/Tree/Table is skipping one row.

This bug is present on the Pre integration Dev WS (7u4 - b11)

To reproduce:

1. Run SwingSet2 using this PIT build (b11)
2. Switch to List demo
3. Click the first item on the left list
4. Try to switch to the next/previous item using the down/up arrow
5. Notice that selection focus is moving to the current item +/- 2 not the current item +/- 1

Same issue can be noticed on the table and tree demos.

Also in the tabbed panel, pressing left/arrow is switching to the current +/- 2nd tab not the next tab.

Try to repeat the same scenario with the b227 (previous promoted build), works as expected so this is a regression coming from one of the recent fixes from the dev ws.

This issue could be reproduced on MacOS X - Lion, still needs to be tested under other platforms.