Is it from the same member? Well if he mistakenly sent it twice or thrice would be somewhat understandable but 10 times? That's utterly spamming and PM rights to that member should be removed up until when or it just might be a BUG like what you said.
Hrmm. Well he may be PM bombing you, is it advertising messages? or it may just be a bug or he may have refreshed the PM sent page many times that caused it to be sent 10 times!
Don, only from one member but I have stopped receiving the PM's. Maybe the other poster was correct in saying the sender was refreshing his browser?
I think Shawn could definitely answer this question. He might be doing some experiments as we speak. lol