I have a Roku express which I have had for over a year and have had no problems until about a week ago when I started having issues with the navigation keys not responding when pushed then when they did respond they continued to scroll up or down, left or right. I thought it might be the batteries and changed them to new and problem persisted. I unplugged the Roku devise for a few minutes and replugged and initially it seemed to help but problem came back. I then ordered a new remote and that didn't help either. Today I purchased a new Roku Express and got to the step to input my Wi-Fi password and couldn't because it would't stop scrolling up or down or right or left. The buttons don't seem to be stuck on any of the remotes old or new. I am using the device on a 32 inch ELEMENT HD TV. Don't know what to do.
It sounds like some kind of IR interference. Sunlight can cause problems as can a remote stuck in a couch cushion. If you stand really close to the Roku and shield it from any other light source does the remote work?