sorry to say but the SB6190 is plagued with a bad chip. PUMA 6. has latency issues from modem to device ie router/computer. if you have speed more than 300 you will see issues. I have upgraded to the sb8200. so far very good does get a lil warm but when cox connection quality in Gloucester, VA is working its blazing fast. Also look in to MoCa filter. If your neighbors has a MoCa network like the panoramic wifi or contour and does not have a filter on their end the network may cause interference with your cable lines.
I wish you luck buddy and the SB6190 will continue to degrade until the new firmware that may get released fixes the issue.
back in January I lost all my hair trying to figure out my issue with the SB6190 but I agree every time cox upgrades a speed their is network issues for at least 6 months as they fix all the week points and upgrade node sites for the increased throughput.
my issues a few months ago http://forums.cox.com/forum_home/internet_forum/f/5/t/20010.aspx?pi287=2
