Sending null byte to serial port in Windows using PySerial?

[sundae]

Hi all,

I'm having troubles sending the null byte (0x00) to the serial port in
Windows using PySerial on ActivePython 2.2.1 build 222.  Currently I'm
doing something like this:

com = serial.Serial("COM1", 9600, timeout=1)
 -- <some data transfer on the port> --
com.write(chr(0))

The device should reply a single byte upon receiving this byte, but I
never got anything in reply.

I looked at PySerial's code, which calls win32file.WriteFile() to
write to the serial port.  I also checked out USPP, which
unfortunately threw an exception when I called read().  I suppose it
wouldn't make a huge difference anyway, since USPP uses win32file for
the underlying communication as well.

Have I missed anything?  Should I use some other method to write the
null byte to the serial port?

Thank you very much for you help!