set IP to auto, look up DNS servers in your area (check with your internet provider for regional servers) and manually set the DNS servers IP address(s).
if you are trying to stream movies through multiple floors you are going to run into connectivity issues. does the issue tend to last longer when you are closer to the wireless router, or does the frequency increase the further you are away?
check your internet settings try to configure allocation of cache your system can hold/clear your cache