I am having some similar issues. I have RR .. had the SB51xx modem and purchased a SB6141, got it 4 days ago.
While my SB51xx was rock solid for years, the SB6141 is terrible and is rebooting itself every 1-3 hours or so. The signal levels all seem fine, according to Motorola's specs. -- Plus, hey. the old cable modem was perfect for years, although it was docsis 2, and the sb6141 is 3.
I did an online chat with RR's tech support .. the guy said "you have old firmware, go to Moto and install newer." I didn't think that was right, since Moto doesn't have firmware on their site and believed firmware needed to be pushed by the ISP. He didn't believe me. I verified this with Moto, naturally.
Question: Someone with a SB6141, can you tell me what your firmware is? Here's my info from »
192.168.100.1/cmHelp.htmModel Name: SB6141
Vendor Name: Motorola
Firmware Name: SB_KOMODO-1.0.6.3-SCM03-NOSH
Boot Version: PSPU-Boot(25CLK) 1.0.12.
Hardware Version: 7.0
Firmware Build Time: Aug 18 2011 10:27:53
The bigger question is .. if I get them to push a new firmware .. will that even help? It's really maddening how often it is rebooting .. I think it's the log entry "No Ranging Response received - T3 time-out" that puts it into a death spiral.