Unfortunately that is all wrong.
First off, you absolutel HAVE to use Gameshark version 4 at the same time as this, or else the sharkport will not function. That is why the second guy gets the error. The first guy is probably because he did not plug in his sharkport at the correct time during installation, and now his computer is not recognizing it. Uninstall it, and then reinstall following the directions carefully.
These guys if they just recieved their sharkports, are recieving the version made by madcatz. So for the guy who asked if anyone got it to work yet, yes I have, and i can use it with MK's with some patience.
I have a guide on how to make it work. You will need a PS2 "SAVE BUILDER" which you can find a link to on my web page. Find the link to my website in my sig and find my guide to using the new sharkport. Go to the link in that article and search for the save builder, and then read my guide and follow it. Happy hacking.