I'm having an issue with my nextbox (Ontario). It began counting down (r---) and then it would boot up with the Cisco logo popping up. After it would say Err:53, and begin counting down again. It's been doing this for several hours now.
Even if other boxes in the home are not affected (which is not certain based on the OP's post), I still recommend that the signal be checked first. Some boxes and areas of your home are affected differently. Please call Rogers and have them check the signal at your home and in your neighbourhood. They can do this remotely. Most boot issues are related to a poor signal. Here's a post on the topic. What is the model number of your box?
The 8642 is pretty old, so it could certainly be failing, however, the signal is always the first thing to look at. You could also try swapping the boxes around in your home to see if the issue follows the box or stays with the "location".