Amazon is notoriously bad for VOD and quality and bandwidth, that being said, I have a much lower speed plan than you and I never get that message. SO you may want to try a couple things. If you're wireless then it may just be interference, and you can correct that by changing the wifi channel in your router.
open a browser, and go to http://192.168.1.1 user name is admin. and the password is most likely the serial number found on the service tag of your VZ router unless you changed it. Once you login succesfully, go to the top and hit wireless, then on the left basic security. then go to option 3
like the above poster said and change it from auto to 11, put the check mark for keep settings after reboot, save it and try it.
if it doesn't like 11, change it to 6, if it doesn't like 6 change it to 1.
you should really only use those three channels. one of them will be your magic number
