Logged In: YES 
user_id=21627

What shell is this in? I cannot reproduce this in a cmd.exe
window. However, that you report the version as "Windows 5.1
(Build 2600)" and not "Microsoft Windows XP [Version
5.1.2600]" (as ver.exe does), and that you use just ">" as
the prompt suggests you might be using a different command
interpreter.

Can you please add

print sys.stdin.fileno()

into the script? On my system, it gives "0".