Steps to reproduce the problem:

1. In a computer with no Ansicon installed, create a file named test.js with the following content:

SHELL = new ActiveXObject("WScript.Shell") ;
WScript.echo( SHELL.run('cmd /c echo hello', 0, true) ) ;
WScript.echo( SHELL.run('cmd /c non_existing_command', 0, true) ) ;

2. Double-click the file to execute it. The result is a number 0 and a number 1.

3. Now, install ansicon and run test.js again. The result is a random number twice.

Tested OSs:
Windows XP x86: pass
Windows Vista x86: fail
Windows 7 x64: pass