qemu-0.13.0-r2 special keys different when using -alt-grab

I use -alt-grab with qemu-0.13.0-r2 and special keys like Ctrl-Alt-f for full screen did not work for me with a windows guest. They work normally when omitting the -alt-grab startup parameter.

After quite a long time, I found out that I have to add the shift key to the keys from the documentation when I use the -alt-grab option.

Probably -ctrl-grab behaves similarly. It would be really nice to have this documented in the default documentation in the man page as has not been documented there yet.