One thing I found out when I was looking for the web pages is that there is no web page, apparently inside the Toshiba. The Motorola surfboard 5120 has a very fine one. But the problem is solved. It took two activities to do it.
The cable guy called into the office and had my Toshiba provisioned for a higher tier of service than the current provisioning was at. I believe it was improperly provisioned in the first place, not in accordance with what Comcast had said was the configuration. Indeed, I was not aware and there is no information on the website that clearly describes the download/upload speeds that are available.
Anyway, they set up what they called 8/1, and that resulted in about the same ol' 2.2 meg down, but about a 1.5 upload. Progress step 1.
Then this week, I had an inspiration. I realized that perhaps my computer has some kind of limitation in speed on it. So I did a speed check on another computer in my home, and it was downloading at 8 meg.
Dr. TCP, doing a change in TCP Receive Window (RWIN)....and reboot, and now I'm pulling down the correct 8 mbits/sec, and I'm a happy customer again.