I have not had an opportunity to do much flying lately. Today I took the P4 out for a quick flight and noticed that the landing was not real smooth. I calibrated the IMU earlier. Everything else looks fine. The take off and the flight was perfect but when the P4 got close to the ground I noticed a little instability. When I landed the landing gear was on the ground and it wobbled slightly until the the motors shut off. I have many flights with my P3P and have never seen this before. Any thoughts?