I have an obi110 and I've made the change to 100mbps full duplex, but I still have trouble with it poisoning the network.
I find if I disconnect the power for more than a few seconds, when I power it back up, within a few minutes to a few hours, the network activity light on the obi110 goes nuts and I can no longer access its webpage or even ping the device. I don't know what it's doing.
At this point, I have to unplug it or pull the network cable for about 10 seconds until it reboots, and then before it breaks again, do a factory reset and restore my settings. Then it seems fine again until it loses power. Warm reboots are fine.
I've noticed this for a few years now. I also have an obi100 and don't experience this problem with it.