I noticed last night that (my) Wii had no problems running a movie as the Roku has buffering issues or numerous lag time issues. Would anyone know why or if there is a fix for this. My thinking is the Roku was made specifically for this so why all the issues? I have 50mg cable internet.
The Wii and Roku use different streams on some providers, so your connection may be traveling a path on the internet that's slower for one device than the other. The problem may also be internal to your network - how do you have each device connected to your home router?
Remember also that regardless of your home internet speed, internet data is only as fast as the slowest link on the chain of computers between the content server and you - typically 8-10 computers on the internet.