c5ride...what bummer for you, especially bothering is the high packet loss..for gamers and downloaders this is impossible. I used ping -n 20 cox.com and at least mine had 0% PL...for now. I've used PingPlotter and WinMTR to test hops, and saw my hops to cox.com had packet losses at various hops....but it didn't seem to bother Cox. My query to my modem did read some outside the range power and SNR....I don't quite understand the ranges that Cox provided for down/up Good ranges (I got an email from their Help).....but at least I was not having down time or issues like yours. All I can say is keep pressing them..for me, I may just try going from cat5 to cat6 network cables, but I'm already using one cat5e to my PC.
I also tried, when using speedtest, and opened the Win TaskManager, go to performance and pick the Ethernet. Then run your speedtest and watch the ranges of the send/receive values and see how they mirror the speedtest. For me, the upload speedtest were about 5-6, while the taskmanager had 11+. User Zurq had mentioned this in another thread.
Just ran speedtest.net to OC from me in OC...181/5.43,