Additional info: I have now used several tweaking programs, and my former 3.08 record has been soundly beaten with a reading of 3.11.
I'm thinking that perhaps my Motorola SB4100 cable modem cannot handle the 5.0 load. I even contacted Motorola via email, and the tech responded that the SB4100 could probably not handle the task. The tech recommended the SB5120 modem. I know Motorola is trying to sell a modem, but is it possible that may be the correct diagnosis?