Did a Pilots n Paws yesterday from Fresno to Petaluma (O69). On my approach to O69 (about 5 miles out), a Cirrus announced he was on the GPS approach (VFR conditions) and announced on the CTAF he would do a "straight in, traffic permitting". Anyway, he as about about a couple of miles behind me and there was another plane in the pattern ahead of me. Nearing the airport, he kept making the same calls, while I announced I would sequence myself behind the plane in the pattern (a Cardinal) and enter base for Rwy 30. I told the Cirrus that I am ahead and of him and planned to make a base entry for Rwy 30. He just acknowledged but didn't say anything more. After another call by the Cirrus saying the same thing on frequency, some one else on the frequency, gently reminded the Cirrus, the pattern is busy. The Cirrus didn't get the hint the first time and kept saying, "straight-in traffic permitting". So when did he not get it that "Traffic is NOT permitting" given the amount of activity on the field?? So after I turned base again, he announced that he would climb out over the runway and enter downwind midfield. I saw him above me as I was about to turn final. If he had continued his approach, he would have probably broadsided one of us. Just don't get it sometimes why some pilots don't have the courtesy that an IFR approach doesn't mean a straight in into an uncontrolled field with a fairly busy pattern.