You are using Gknot .023, the current release is Gknot 0.27. Doom9's guide is a little out-of-date. Your problem is caused by your release of LAME. If you go to the first page in the guide (where all the software links are), you'll see LAME 3.92 listed. Gknot 0.23 came with LAME, but an earlier release that doesn't understand Doom9's recommended "--alt-preset" command. Later revisions of Gknot included DivX 5, BeSweet for audio transcoding, the ability to use .avi or .avs as input (not just .d2v), and other improvements. If you decide to jump to 0.27, install both the Rip pack and the System Pack.