One thing to check, just so you dont undo anything you may have put right, I've found that when the server.exe file doesnt load at all, I need to restart the machine (I'm running XP pro sp1 on the host pc)
Basicall if you change anything in you sql database, or delete your market save files, or change your StrRes3g or !setup txts. It can make this happen, and even tho everything is fine you need to reboot :s