The last time I ran a ping plot after a disco fever episode there was issues with a Telstra router in Sydney that was giving me 33% packet loss over 1/2hr.
I didn't do it after yesterdays episode, but I may today if I have the same issues. The time before that when I submitted the info to Skuzzy he found an issue with a router in the USA on the return path.
I have managed to get a written statement from my ISP that they do not conduct any sort of traffic shaping outside of speed when individual data limits are exceeded.