swa66 - 8:13 pm on Oct 9, 2013 (gmt 0)
Smells like something is forcing a (somewhat transparent) cache in-between it all.
I'd look at both ends to the packets transmitted. It they do not match up: you've got a clear case of that. Note some ISPs (notably VSAT operators) use "acceleration" technology that's totally wacko in what it does to TCP connections. I'd expect weird results there.