Actiontec M1000 modem help

I have a this modem and problem about every other day it drops my connection speed. I have quest and I can access my modem and see the I am getting 5m but the speed test says other wise at 1.5 -2 megs. If I unplug the modem and reset its fine for a little bit. Does this sound like a modem problem? Or am I dealing with something else. I have one phone line with no filters and it seems like my connections are good, and quest says I'm getting the speed.

I just ran it again after doing nothing and Im back up to 4400kp down and 700 up, I also have a linksys router that I uplugged and only had my PC on the modem and it still did it.