No, it's not just you. It has happened more than you've noticed. I've posted messages that end up being repeated 3 or 4 times in a row, and I've seen other posts that have repeated also. I've noticed that it can take about 15 to 20 seconds for a post to load and since I don't see the loading bar at the bottom of the screen, I think that my mouse click didn't work, so I try it again. Watch the "STOP LOADING" icon that is right next to the "REFRESH" icon, that should indicate whether your post is loading. The number of times that the post repeats, depends on how many times you click the mouse. I've also noticed that my mouse click does not "take" (is inactive, and has no effect) until I move the pointer (after clicking). In other words, if you click the mouse and leave the mouse pointer in the same spot, it will be as though you never clicked the mouse.