changing channels is getting to be a chore.........remote not very fast, or not fast at all
How old is the remote? Have you changed the batteries?
You can get the remote replaced "free" at a Comcast service center. Also; pull the plug on the Comcast box. Wait about 2 minutes and plug it back in. After at least 5 minutes, turn the cable-box back on. That would correct any errors causing the box to be your problem instead of the remote.