I'm running VirtualBox on a Win7 host. Guest OS is Centos. My setup is a laptop (screen 1) with a huge external monitor (screen 2). I'm only telling Centos there is one monitor though.
When I start up VirtualBox on screen 1, the mouse capture works fine. I don't have mouse integration because (I think) the kernel on Centos is too old to support it. That's fine, I don't mind doing the Right-Control thing.
The problem I have is that when I drag the whole VM window over to my second monitor, the mouse capture doesn't work right anymore. I click inside the VM and can move the VM cursor a little bit, but I can't always get to the edges of the VM screen — before I get all the way to an edge, the cursor will escape from the VM as if I had hit right-control. But it's still captured according to the icon, and if I then hit right-control, the guest cursor jumps to a different screen location.
My workaround: if I have the VM window mostly on screen 2, but a small corner of it still on screen 1, then the mouse capture works correctly.
Is there a setting to make this work better?