I put a four port powered Belkin USB hub into the usb slot on the apple tv. I attached two Seagate 1.5 HDs. One had movies; the other had TV shows. Both showed up on NitoTV. No crashes. Tests running file from both HDs showed no problems. No crashes, no finder restarts. Just want to pass it along to the community since I believe using smaller HDs minimizes the risks of disk failure and loss of all data. Cheers!
Belkin hubs always seem to do the trick