Steps to reproduce the problem:
(1) Launch ADS.
(2) Created 3 QA tabs in the order as QA-1, QA-2, QA-3.
(3) Press Alt-1
    --> QA-1 becomes the selected tab
(4) Press Alt-2
    --> QA-2 becomes the selected tab
(5) Press Alt-3
    --> QA-3 becomes the selected tab
(6) Press Alt-2
    --> QA-2 becomes the selected tab
(7) Right click QA-2 tab header and select 'Floating' to get QA-2 displayed in a floating window.
(8) Click ADS title bar so that ADS man window will get window focus
(9) Press Alt-1
    --> QA-1 becomes the selected tab
(10) Press Alt-2
     --> QA-3 becomes the selected tab (QA-3 now is the second tab displayed in tabbed pane)

Based on above behavior, it seems that Alt-N hot keys are only applied to tabs displayed in tabbed pane but not those displayed in floating windows.

(11) Continue from step 10 above.
(12) In QA-2 floating window, click QA-2 tab header and select 'Docking' to get QA-2 tab restored in tabbed pane.
(13) Press Alt-1
     --> QA-1 becomes the selected tab
(14) Right click QA-1 tab header and select 'Floating' to get QA-1 displayed in a floating window.
(15) Click ADS title bar so that ADS man window will get window focus
(16) Press Alt-1
     --> QA-1 floating window is brought to front and QA-1 becomes the selected tab
     Is this the correct behavior? This behavior conflicts with the result of step 1-10.
(17) Click ADS title bar so that ADS man window will get window focus
(18) Press Alt-N, where N > 1, while ADS main window has focus
     Alt-N hot keys stop working once the first tab becomes floating