QEMU crash after sending data on host serial port

Good morning,

I'm using QEMU for Windows last version.
The host system is Windows 7 64bits.
I'm excuting the following statment :

qemu-system-x86_64w.exe -hda debian.img -m 256 -net nic -net tap,ifname=TAP32 -soundhw all -serial COM9

Qemu starts the emulated Debian and it runs correctly.

If I try to send data from Windows using COM9 to QEMU (both "real" or emulated by the COM0COM driver), QEMU crashes. Windows dump available if required.
If I try to send data to /dev/ttyS0 (that should be the Linux side of COM9) from Debian, again, the wirtual machine crashes.

More details if necessary
Best regards
U.Poddine