Populate your StartupLocation Table.
You need to enter values in there that will try to match your "character created" constraint to select the available Startup Location.
You need to provide a valid X/Y/Z/RegionID coordinate in your SQL Record, and you can set all the constraints to "0" to match EVERY character, and they will all spawn at this same location !
If you want to enter specific constraint (at least Realm Match to start them in their own realm...) you can specify Realm ID, Class ID, Race ID, Requested Client Region ID (for some old client that allow to start in Shrouded Isles or to choose not to run the tutorial !), and the startup script will try to match your character to the new constraints or will default to a record that use "0" constraints.
There are some tips in this topic :
http://www.dolserver.net/viewtopic.php?f=59&t=22332 to create your startup location table if you don't have them already created in your database !