I haven't noticed anything.
I use this to diagnose connection problems
http://www.d3tr.de/
If three of you noticed it and no one else did, run the trace to the server and let it run in the background. If you find a hop that you have in common that's throwing spikes, you can inform the owner of that node. A lot of times when ISPs blame the destination and the destination blames the ISP, the culprit can be found in some obscure failing hardware halfway up the backbone.
Not always the case, but either way, it's an epic diagnostic tool.