It's fairly common that a thread will come up with a complaint about the last quarter turn of a razor being a little sticky or difficult to turn. The response I always see is to let the razor soak for a few days. This often works, but it takes time. I received a Slim today as a slightly early present from my sister. The last quarter turn was a problem, and after a few hours of soaking it in hot, soapy water it didn't seem to help at all. I used some unwaxed floss to floss the area between the handle and the top of the knob that turns. I did this for about 30 seconds, and the mechanism worked perfectly! I'm not saying this is going to be a fix every time, but this is a method I haven't seen mentioned before and I thought it was important to share.