Two points, just in case: You must have a blank line between records (After a Disallow line and before the next User-agent line). And you need to write your robots.txt file using an editor that will not put carriage-return/linefeed pairs at the end of each line. robots.txt is a Unix file, and it only wants to see a linefeed. I use Microsoft Word in ASCII mode with "Linefeed Only" selected when I have to work on a robots.txt file on a Windows sytem. These options are available in Word's "Save As" dialog box. The Notepad editor will put CR/LF pairs in the file, and it won't validate.