Flaky Cox BB connection

For the last several days, my Cox BB connection has been highly erratic. Before I get into it with the geniuses at Cox, I'm wondering if anyone could point a likely cause for the following assemblage of symptoms:

--Most sites time out on the first attempt to load. On second or third try, they will load, but often incompletely (minus graphics and media files). Some "Unable to connect to the internet" error messages mixed in.

Often a site will in fact have loaded but not be displayed. The brower displays a white screen with a "Connecting...." message in the lower left corner. But if you click anywhere, suddenly the site displays. As thought the "finished loading" message was missed.

Other times, the site displays, but the "Loading" animation in the tab continues.

Takes a long time for an audio stream or video to start playing, but once it does, it streams with few problems.

I have occasion to upload large media files, and that's working just fine. Downloading is the problem.

Is this definitely a problem with Cox's network? Could it be my cable modem, perhaps?

Yes, I've rebooted and reset the modem repeatedly, to no effect.

Any knowledge would be much appreciated.