A bit ago I posted about getting a Western Digital My Book World WDG2NC10000 1TB box. I had it drop off the network a couple times and stopped trying to move data over to it en mass until I could resolve the problems. After digging through one of those crappy knowledge bases (when will people learn what a wiki is?) I found this: “If there is heavy I/O load put on the network and WD My Book World Edition hard drive, it is recommended that a static IP address be used rather than DHCP.” with no explanation.
I switched to a static IP and I’v moved 50gb or so now without it dropping off the network onces, whereas before it’d drop somewhere around 10gb or so. Working much better now.