Thanks for the report! The difference that you were seeing was due to Amazon's "showing most relevant results" feature, when it randomly decides to filter out results that it deems less relevant to your search. I personally find that feature annoying, so I found a way to work around it and added the workaround to so.cool's code. Check it out. You may need to do a full refresh of so.cool (Ctrl-F5) to pick up the code change. The result count should be the same now for both of the sorts methods, I get 273 for your exact search.
You, my friend, are a genius! GOOD JOB IT WORKS!! :-D