Here's what I know. At 3:17 pm Eastern, you visited the thread
Birthday Announcement and posted post #13 there.
Exactly one hour later, your browser made a call to the server, possibly requesting the thread be redisplayed.
Exactly one hour later, it tried again.
Exactly one hour later, your browser started making about ten requests a second to redisplay the thread.
It's worth trying Firefox but I don't know why this would happen in the first place...