Just had a reply back from one of the tech guys at play.net.
Here's what the deal is:
These are always tricky because of the authentication system. When you go to login from our website, the system sends down a <name>.sal launch file, the contents look like this:
What all of that means is:
UPPORT=5535 The authentication server and port
GAME=STORM The front end system, there are two options, STORM and WIZ depending on which instruction set you're getting. The simple version, WIZ or the more in depth version STORM with xml support
GAMECODE=DR The game, there are 12 player options here depending on the game and game instance, and even more for GMs
FULLGAMENAME=StormFront The full name for the front end
GAMEFILE=STORMFRONT.EXE The executable that will run
GAMEHOST=storm.dr.game.play.net More server instructions, if you were using the Wizard it's prime.dr.game.play.net, and this changes from game to game and instance to instance. Platinum is different from prime, Gemstone is different from DragonRealms, etc.
GAMEPORT=11024 The port the game is running on, this also changes depending on the instruction set (DR for the Wizard runs on port 4901 for example)
KEY=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx The key assigned by the login server to get the character into the game. These are time sensitive, so the same key probably won't work for the same character even later the same day.
All of that gets assigned by the login server (which is separate from the authentication server) running on port 7900.
There are a ton of reasons why it would hang up and fail, but mostly it's because what we do isn't like other MUDs. Not taking any of those things into account can mean you get halfway there, but not all of it. My best recommendation for getting through it isn't us, yes, they're our games, but this isn't something we normally deal with, but checking in with a couple of the other third party client builders, the folks who make Lich (mostly for GemStone), Genie (mostly for DragonRealms) or the guys who made Warlock (mostly for DragonRealms, but Linux native). They'll have been through a lot of what you're looking at, and done it from the side of trying to get their systems running. Warlock might be your best bet since they don't sell theirs.
Every front end is different, and knowing what might need to be tweaked is more than I can answer because of those differences.