They are being sent to Arena either because the expansion variable isn't set high enough or the zone is set to a higher min status or something. If you don't want SoF/SoD chars starting in Crescent Reach or wherever, you can just set the following rule to -1:
Code:
1 World:SoFStartZoneID 394 Sets the Starting Zone for SoF Clients separate from Titanium Clients (-1 is disabled)
If it is set to -1, all clients should start in the same start zone as they would in Titanium.