This bug is observed on all platforms and on GTK LAF.

If the user selects a tab using key board and then traverse using the arrow keys,
the focus traverses but the corresponding panels are not shown.
And the tab with title "Bouncing babies" is not selected at all. This is observed in SwingSet2 demo.

Setps to reproduce:
1. Select Tabbed Pane demo.
2. Click mouse on the first tab or traverse to first tab using tab key.
3. Now use the right arrow key to go to next tab.
4. Next tab is selected but the corresponding panel is not shown.
5. The "Bouncing babies" tab does not get selected, instead the focus go back to the first tab.