Description of problem:
a.the issue occurred on win7 64 guest  
b.savevm&loadvm snapshot while changing memory balloon size in monitor

Version-Release number of selected component (if applicable):
qemu-kvm-0.12.1.2-2.209.el6.x86_64
kernel-2.6.32-216.el6.x86_64
How reproducible:
80%

Steps to Reproduce:
1.install and boot guest with the following cmd
  /usr/libexec/qemu-kvm -M rhel6.2.0 -usb -device usb-tablet -cpu cpu64-rhel6,+x2apic -enable-kvm -m 2G -smp 2 -name win7_64 -uuid `uuidgen` -monitor unix:/tmp/tt,server,nowait -rtc base=localtime -drive file=/home/764.qcow2,if=none,id=drive-virtio-disk0,format=qcow2,cache=none,werror=stop,rerror=stop,aio=native -device ide-drive,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=2 -drive file=/home/en_windows_7_ultimate_with_sp1_x64_dvd_618240.iso,format=raw,if=none,media=cdrom,id=drive-ide0-1-0 -device ide-drive,drive=drive-ide0-1-0,id=ide-drive0,bootindex=1 -drive file=/usr/share/virtio-win/virtio-win-1.4.0.iso,media=cdrom,cache=none,werror=stop,format=raw -monitor stdio -qmp tcp:0:2222,server,nowait -spice port=5933,disable-ticketing -vga qxl -netdev tap,id=hostnet1,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet1,id=net1,mac=00:1a:4a:30:2a:21,bus=pci.0,addr=0x8 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,vectors=4,bus=pci.0 -chardev socket,id=channel0,path=/var/lib/libvirt/qemu/win764.channel0,server,nowait -device virtserialport,chardev=channel0,name=org.linux-kvm.port.0,bus=virtio-serial0.0 -chardev socket,id=channel1,path=/var/lib/libvirt/qemu/win7642.channel1,server,nowait -drive file=disk4.raw,if=none,id=drive-virtio4,cache=none,werror=stop,rerror=stop,readonly=on -device virtio-blk-pci,drive=drive-virtio4,id=virtio-blk-pci4 -device virtio-balloon-pci,id=virtio-balloon1
2.install virtio-balloon driver from Device Manager in guest.
3.in monitor
(qemu) savevm ee
handle_dev_input: stop
(qemu) loadvm ee
handle_dev_input: stop
handle_dev_input: start
(qemu) balloon 1000
(qemu) info balloon
balloon: actual=1000
(qemu) savevm ff
handle_dev_input: stop
handle_dev_input: start
(qemu) balloon 800
(qemu) info balloon
balloon: actual=800
----------------------------hit BSOD
(qemu) loadvm ee
handle_dev_input: stop
handle_dev_input: start

Actual results:
QE hit BSOD and had to reset guest.Strangely,the BSOD code wasn't unique,on the contrary,it was always changed every time.
Expected results:
Guest comes back to be active and works well.

Additional info: