I did get a new router (from the ISP) a couple months ago to replace the one I bought myself that was horridly out of date that had less throughput.
Cox's infrastructure is a bit dodgy at times. During some parts of the day a tracert will show packets lost to the void.
That said, again, as I mentioned I don't know where the download mirrors themselves are, but I have seen a number of 500 errors from the hard-light.net site over the past weeks (though some of errors were masked by your host's "view cached copy or try again for a live site" page).
I think it's a combination of issues on both ends to tell the truth.
I'm not having any problems, and I'm not seeing anyone else on here reporting problems either, and I'm here every single day several times per day. So, based on that and based on what you said here, I'd say that it's either all on Cox's end, or it could have something to do with the cables that are in your walls - or it could be a combination of both. For example: a few years ago, I had to have Comcast come out because I suddenly began having some serious connectivity issues. I had intermittent connectivity, and when it WAS connected, it was slow and weak (lots of packet loss and very high ping). In addition, during those brief times of being connected, our digital phone signal was choppy. This was the result of the severe packet loss.
So, as I said, I had to have Comcast come out. The tech who came out did some tests and discovered that the cabling in my walls was the old RG-59 that was installed back in the late '80s when we had Cable TV installed. They said the reason why I was experiencing problems was Comcast did some upgrades at the "home office", and that resulted in my RG-59 no longer being good enough to handle the new signal. So, the tech ran a very long RG-6 cable (the new standard) directly from the outside wall all the way to my cable modem/phone modem thing (some Arris-brand unit). The outside wall connection is where the "Drop Cable" comes in. The Drop Cable is the cable that connects directly to the house. I think that he even had to replace that one too. Oh yeah, he also gave us a Subscriber Amplifier which helps boost the signal. It gets installed inside the home right where the Drop comes in.
Now, you might think that running a really long cable was a sloppy and lazy solution and that the cable was an eyesore (ugly to look at). Fortunately, not only was I close enough to where the Drop comes in that it was no big deal, but we also had the ability to hide the entire length of the cable! If you're wondering about the cabling for our TV, we were fortunate enough that we already had RG-6 over there because it was a newer installation due to no longer having our TV in the old spot where the RG-59 was (the original installation from the '80s). So, it worked out pretty well!
Anyway, so yeah, I truly believe that the issue you're having is either all on Cox's end, or it's all on your end, or maybe a little bit of both. There's even the possibility that something outside needs to be upgraded as well, such as your Tap (but this shouldn't cost you anything since it's their equipment). It's not really YOUR tap, but you are using a part of it. Each tap contains a number of ports (they're identical to the stubby "jack" that comes out of your wall), and your Drop is connected to one of those ports. If the tap is old and outdated or if it is no longer functioning properly, then it could be the source of all of your problems as well - provided that you have nothing but RG-6 or better (including the cables in your home that you can replace yourself - you don't want any bottlenecks). There are other things outside that could be the source of the problem, but fortunately, if it's a problem with something outside then you shouldn't have to give them any money to fix it because it's all THEIR equipment. I don't know if this includes the Drop though. I would think that Drop replacements require the subscriber to pay for it, but I'm not really sure. Either way, I'm about 99.99% sure it's not on HLP's end (I'm always afraid of being wrong, so I refuse to say that I'm 100% sure even though I actually am).