I was in the Bell store this week swapping out my phone. While in there, I overheard one of the staff telling a customer that there has been a known issue with the Sympatico modem/router's power adapters. I asked her after about this and she's been swapping about 30 a day over this problem.
SO, if you're on Sympatico and having issues with your connection going out, call Bell and steer them into approving a swap-out of your power adapter.