Mouse capture in 2nd screen doesn't work

[Johnny]

1. Start a guest (in my case a Windows XP)
2. Drag the window to the full screen (multi-head extended desktop setup)
3. Notice how that the mouse slips off the guest before the pointer inside the guest doesn't reach the edge

host is a Windows 7 64bit guest is windows xp guest additions are off, mouse integration are off. I just want my mouse to be captured and stay inside the guest when the focus is on the window until i press the host key.

while searching for the solution i bumped into this post, same problem as mine: ​http://superuser.com/questions/242705/how-can-i-get-mouse-capture-to-work-in-virtualbox-when-i-move-guest-window-to-sec