Much like the original poster described. I now am getting the sine wave audio and then game crash. Earlier today, I was in the Claw of Jormag Event and I was able to complete it without issue. I signed on again this evening and attempted the SAME event and was dropped from the game.
I keep my system updated constantly, however, there were no updates that were installed today. Seems that SP1 isn’t the correct solution to this problem.