Always mouse grabbing with -usbdevice tablet

version: QEMU emulator version 1.0 (qemu-kvm 1.0)
             QEMU emulator version 1.0 (qemu 1.0)
             (source builds)
os: archlinux x86-64
last working version: qemu-kvm 0.15.1

commandline: each with "-usb -usbdevice tablet" and sdl output 

expected behavior:  mouse gets grabbed only by forcing it (pressing release/grab-combination (CTRL-ALT))

actual behavior:
When moving the mouse over the window it gets instantly grabbed, so i cannot use window-manager-specific hotkeys anymore.  After pressing the release combination every mouse movement over or within the window will grab the mouse again. 
I have tried this with several vga types and window managers: no difference