Thanks, Ptarp, that is what I had figured as one of the possible causes since that went in right about the same time as the Steam Client version.
Derision, if you want to check it out, but don't have SoD yet, or an account to try it on, I will buy you one if you want to just send me the email address you want it gifted to from Steam

We can use all of the help we can get.
KLS, Secrets and I briefly reviewed some collects to compare SoF>EQEmu with SoD>EQEmu and SoD>EQLive and so far they do look pretty similar. It seems 2 extra bytes were added to the end of the second packet that gets sent from the Client (after the OP_SessionReady from the client and the OP_Login from the server). And the server reply to that packet is a bit different in structure. So, at the very least, it looks like they have changed the structure a bit. We are not sure if encryption has been changed yet.
I may try setting up the Open Source LS to just send me a Login Accepted packet no matter what, so I can at least log in with the SoD client to continue work on it while the LS stuff is being worked on.
On a side-note, it looks like SOE may be considering an idea I mentioned a year or 2 ago on their forums to allow custom content created by players. When logging in to collect packets, here is one of the vote options I got:
"Player generated content system - Allow players to place NPCs and traps, set mission types, and turn loose their custom zone for other players to experience and gain points in a scaling reward system"
My idea was for custom player run servers, but this would definitely be a stepping stone toward that!