Q: Why do I get the "The last posting from your IP was less than 360 seconds ago." error when I haven't posted today?
A: Logging in, sending PMs and reporting posts to a moderator will also be counted as posting and extend this limit back to 360 seconds. Don't worry: as your activity increases, the 360 second limit will decrease as well. Here you can see the algorithm how the posting limit is caluclated based on your activity: https://bitcointalk.org/index.php?topic=237597.msg4131557#msg4131557