Normally when I copy files across my local wired network they go at nearly full network rate, 95Mbps on a 100Mbps network. With a new S1100 blu-ray player connected, the rate varied wildly between 5 and 90 Mbps, averaging about 30. I soon proved the S1100 to be the cause by unplugging it and the rate was immediately restored.
After some puzzlement and disappointment I saw the Quick Start option explanation - and turned it off. This does - when the unit is off - prevent the disruption. So if I want to copy large files across my network I will need to make sure that Quick Start is off and the unit is switched off.
Sony might wish to comment on why the S1100 causes such disruption.