having problem with my Airport Express when streaming tv with roku

I am streaming movies through my airport express and was told by Roku that I need to have Apple change the SD settings for my router. We have the 802.11n Wi-Fi. Every other movie stops in the middle and says "loading "name of movie"" and we cannot see the rest of the show. I was told that Apple has to correct this by resetting the router. I have a cable provider and they also said they show that the error is with the Airport from Apple. We have turned the connector off and on hoping that would do it but it is something that has to be done by apple. Is there a way to fix this on my own. Any help would be appreciated.