All I know for 5 is this:
This version follows the regular notpron thing. Ex: Level 3 has the same "change the address", and 4 requires you to turn up the brightness. As for this one, I know the original has something to do with the source code of the site. It wasn't as helpful here, this is what I got:
<html>
<!-- I feel as if I'm being tricked -->
<head>
<title>Fraudulent imagery</title>
<bgsound src="../sound1.mp3" loop="infinite">
</head>
<body bgcolor="#000000">
<center>
<img src="../ozcarism/screen5fake.jpg" width="640" height="480" border="0">
<br>
<br>
<font color="#FFFFFF" size="5" face="Arial">Pass the sALT</font>
</center>
</body>
</html>
The only other thing I can think of is that in the original notpron, it has to do with an anagram. And the address bar has this: dnuorayawgnorw
Any ideas as to what that might be?