Thank you both for the quick info. I have a fast Cox IP connection but it is known to vary, especially at high usage times - I live in the sticks. I was wondering why, if the buffer is huge, it wouldn't "store" the program so that you could watch with guaranteed HD. That would be a huge selling feature and propel ROKU and NEtflix into major selling point at any connection speed. My Satellite box does it on a hard drive. With ROKU 2 why didn't they get with it?
My ancient ROKU box does rebuffer and drop quality at the same time.
No Roku has a "huge" buffer. They have a small one that gets a bit bigger on the newer boxes but none buffer more than about 5 or 6 minutes of video and it may not even be that much. The small buffer is not really the limiting factor on streaming speed it is rather the connection speed.
As I said in my first post in this thread the extra memory (microSD) that can be added to Roku2's is ONLY used for storage of the channels that are loaded. It is not used at all for anything related to streaming.
Because of licensing and other issues Roku does not "download" it just streams and streams very well. Some Rokus can have a usb drive plugged in but that is only used for playback of files stored on it.
Roku made the decision to go with an inexpensive model that does one thing (streaming) quite well and they provide an SDK that allows people to create chs that can add functionality and content but they have stayed away from any subscription based service so that means that a lot of things you see on subscription based devices like your satellite box will never be seen on the Roku.
Try another DNS or see if you can improve your connectivity and, usually, you will see a good improvement in Roku's streaming. It takes a connection of 3mbs or even less to stream most HD so, even when your connection slows, getting HD is quite possible as long as the stream can get to your Roku without much of lag or delay.