Same problem I faced right now. But in my case I came up with fresh installation.
I tried " [url]http://192.168.1.100:81/fog/service/Pre_Stage1.php?mac=00:13:a9:f3:3b:2a[/url]" and result is
[SIZE=4][FONT=Times New Roman][COLOR=#000000]" ##@GO "[/COLOR][/FONT][/SIZE]

[SIZE=4][FONT=Times New Roman][COLOR=#000000]Any Idea??[/COLOR][/FONT][/SIZE]