I am seeing a (I think) new problem in DF 3.41 beta 12 with Outlook 2010 Sp1 x86 on Win7 x64.

I have multiple Outlook 2010 Windows open, showing different folders: Calendar, Tasks, InBox. On my secondary monitor, I have Calendar window, Tasks window and I open the Address Book (connected to Exchange) and move it to the secondary monitor. When Calendar or Tasks window have focus, and I hover over the grouped Outlook button in the DF taskbar, and then click on the Address Book preview, the Address Book pops up over the other Outlook Window (I think this may be Aeropeek), and then the wrong window is brought to the front.

An incorrect window to the front also happens when I click on the Calendar or Task windows, even if I move the Address Book back to the primary monitor.

Update: tried with Beta 12

In testing this, I also had one occasion where I clicked on the Calendar preview, the Calendar window came up, I clicked on the taskbar Outlook button, the Calendar window minimized - note that I have LastActiveClick active and it should have cycled to the next Outlook window. Once my click was ignored. In general, there seems to be some interaction between how fast you click the taskbar group button after clicking a preview - if you click before the preview can drop down again, sometimes weird things happen.

Beta 13 has the same problem. 3.4.0 does not exhibit the problem at all.

Interestingly Beta 13 and 3.4.0 order the three Windows in the preview pane differently and that seems related to the issue - clicking a preview often brings up the same wrong window, like the previews are not hooked to the right window when clicked.

Just out of curiosity I turned off LastActiveClick (I see you aren't caching the registry value) and the problem went away. Also, the problem doesn't seem to occur when a non-Outlook window has focus - I can bring up an Explorer window, click one of the Outlook group previews and get the right window most of the time. However, clicking on a different Outlook preview with one of the group having focus, causes the wrong window to come up.

BTW, I just noticed the same problem occurs with multiple tabs in IE 8.

Beta 14 seems to be working much better - but I was able to cause a glitch.

Sometimes when I clicked on a preview to bring it to the front and then immediately clicked on the taskbar group icon, rather than moving to the next window, the click caused the top window to minimize (I don't know that you can minimize a group member on the Windows 7 taskbar).

I also noticed a LastActiveClick behavior that I didn't know about - I'm not sure how the regular Windows 7 taskbar works, but if you control click a group icon with LastActiveClick turned on, and the preview drop-down is showing, the aero-peek switches to the next window, so ctrl-clicking the group icon cycles through the aeropeek of all the open windows in that group.

Glad you like the LastActiveClick behavior - I find it very useful!

I was testing with Outlook 2010 using a Calendar window, Task list window and the Address Book window.

I tried testing in Windows Explorer and found a new issue, but couldn't replicate the minimize issue yet.

If you have a progress box open in Windows Explorer (i.e. copying a 3GB .ISO from a thumb drive) and click the grouped explorer icon, the windows switch until the progress box has focus, then it is stuck - clicking doesn't switch away from the progress box.

Strangely, I just noticed another, similar glitch - copying a 3GB file from a network drive to my local D: drive, with two Explorer windows open, clicking the group icon switched between the two explorer windows, one with the progress box on top, and did not treat the progress box like a separate window though it has a separate preview. OTOH, opening a third Explorer window on My Computer, caused it to remain out of the cycle list - clicking just switched between the two original windows. When the progress box closed, clicking switched between all three windows.

Update: With some further work, I duplicated with Windows Explorer windows as well as Outlook. It appears the key is to move over the grouped taskbar icon, wait until the preview window just appears, then click the grouped icon button. Sometimes it minimizes the current window instead of switching to the next window. You have to click just when the preview window is fully drawn, or just before it finishes drawing perhaps.