"Is" is one of those words that my fingers frequently type "si." Wrote a spoof about it once. "Matter" is also one of the words that my fingers just don't seem to work right on: it always comes out "mater" the first time.
Phil, Probably most (if not all) of the errors were the parts of the post that he copied from my post. The keyboard that I was using was terrible and it kept skipping letters and it was too time consuming to go back and fix all the mistakes so I just left them.
edit: or maybe it was the rainbows and hurricanes that I was drinking?