I use it every day. So try changing the token of the server in the walker panel combo box select the right token for your server:
ps: use the one which say: second std.
If you want o use 10.6.5 you can use Sauron Patcher http://saur.x33.ru/index.html. Go where it say Free version. It works very nice.
when you run it, open your l2walker and check that it says the version (in the patcher) then double click to activate the options. You will see an icon with an image of the sun click on it to activate.