Is there any reason why I keep getting this error message...

[zpm]

An Error Has Occurred!
The last posting from your IP was less than 360 seconds ago. Please try again later.

Is there any reason why I keep getting this error message when sending private messages on this forum?  My posts are not less than "360 seconds" apart.  This occurs even on a first attempt of the day trying to send a message.  Waiting "360 seconds" changes nothing.  It seems as if it is randomly decided for the message to be sent or not.  It's extremely inconvenient and very annoying.  I have learned to copy & paste the message in notepad before sending as I have lost many messages by this forum "feature".

[greyhawk]

"Logging in" to the forums is falsely counted as a "post". So if not enough time has passed between login and your first post attempt you will get the message even though you have not posted yet in this session.