import py.subprocess error...

I tried to call adb shell from a python subprocess

    py.subprocess.Popen(pyargs('args','adb shell', 'stdin', py.subprocess.PIPE)).

But it returned the following error:

    Error using subprocess>_make_inheritable (line 566) Python Error: WindowsError: [Error 6] The handle is invalid
    Error in subprocess>_get_handles (line 532) c2pwrite = self._make_inheritable(c2pwrite)
    Error in subprocess>init (line 382) errread, errwrite), to_close = self._get_handles(stdin, stdout, stderr)

Any idea about why this happens?