If you want expert advise see this thread http://forums.verizon.com/t5/FiOS-Internet/Problem-with-WIFI-slow-speeds-and-Verizon-Actiontec-MI424WR/td-p/463073
If all your devices are wireless N capable; login to the router - wireless settings - advanced security .. - 801.11 mode and set it to performance.
(NOTE the login credentials may vary depending upon what model you have)