Cisco Routers :: RV180 Dropping Connections Every 10 Minutes Or So

I have a cisco RV180 hooked up to a  cisco cable modem and Cox service. 
 
The basic symptoms of the problem are that every 10 minutes or so external connections will hang.  This lasts maybe 20-60 seconds.  If you're loading a website when this happens, various parts of it won't load and firefox will sit and spin indefinitely (it seems) until you manually stop the loading and click the reload button.
 
When this is happening I can still connect to the routers webserver and dashboard that auto-refreshes every 10 seconds.  It seems perfectly fine.  My initial theory was that something was broken on the Cox end of things, but after swapping out the RV180 with an old on-q router we had laying around, we haven't seen the problems. 
 
Some other differences I've noticed between the on-q and the rv180:
 
* with the rv180 traceroute to external hosts shows a big delay (500-600ms) at the hop right after the router.  With the on-q, it's 12ms. 
 
* when I ping the ip of that hop with the large delay, with the on-q I get no responses.  With the rv180 I would get these strange host redirect messages that make it look like that ip is redirecting to itself.  There would be 1 or 2 of those redirect responses, followed by 3 or 4 errors, and every packet would be listed as an error in the ping summary.