As mysteriously as it started, it stopped. Well, mostly.
I logged in yesterday evening at 7 or 8 EST and had no problems until this morning. So far it's only been dropping chat connection but I wouldn't be surprised to start freezing again.
Did that actually work for you? The reason I ask is I run both the regular client and the lama client on dx9, precisely because 11 is a mess. You should be able to do that through the graphics options in DDO instead of altering your dx files.
Yep resolved it completely I was able to play again.