I have read lots of posts about Civic S1 problems shifting into 3rd gear. I bought my 07 new and experienced the same problem. It was not that frequent but occasionally popped out of 3rd. I switched manual transmission fluid to a Quaker Sate Syncro fluid and have never had the problem since and have put on about 5000 miles since the change. The shifting through all gears is better, smoother and easier, high rpms or low. I love this little car and without the nagging shifting problem or the worry that I am destroying syncro rings I can relax and just drive. I have heard of similar cures with Penzoil, GM and Amsoil manual transmission syncro fluid.