Ever since starting the Shaw service a year ago, I had continuous lag spikes about 1 every 3-5 minutes. They're not very long, but they are enough to make online games nearly unplayable. After about 4 months, they went away on their own and things were good, until I recently power cycled my modem/router combo. The wifi had cut out and so I restarted the device and since then, the lag spikes are back. What's causing this? My computer is connected to the router by cable.