Not that it's likely to help the speeds though.
Sounds like you may have moved to a different CMTS and, like many these days, it's showing the strain of supporting 100Mbps unlimited clients.
Try setting up a TBB quality monitor -
http://www.thinkbroadband.com/ping/monitors.html - you'll need to enable "Respond to ping from WAN" somewhere in the advanced setup pages.
Maybe a reboot would help if it's upstream congestion and doing it switches you to a different channel.