I've checked the following options:
1) Taskbar -> Taskbar Button Middle-Click Behaviour -> Move to next monitor
2) Window Management -> Enable middle-click window moving (middle-click on a windows's caption bar)

I am experiencing the following issues - some applications moves to 2nd monitor upon mouse middle-button clicking on its window caption bar, and some doesn't. For example Adobe Reader maximized window doesn't, Skype dialogues and main window does, ICQ main window doesn,t but dialogue window does, explorer.exe windows does and so on and so forth. What's the problem? Can't figure out. I've tried to enable/disable the mentioned optons but it didn't helped.

Hello,

I can confirm this behavior on my PC, see my troubleshooting text - http://chopapp.com/#e8ylzxwz
I've noticed that the middle-click function stopped working, when I moved to beta 7 and is still there in beta 8,
(though I'm not sure, could be it was there in beta 6 as well)

hello Jon,

I've just installed Beta 9, unfortunately, the problem remains the same...

surprisingly, adobe reader seems to work ok on my machine, with beta 10,
I've sent you the log with failing middle-click on firefox...