Questing in RPGWorld is a bit broken.
To save yourself vexation, follow these rules:-
1. Don't have a quest that starts and ends with two npc's that have the same name. E.g. Bill can't give you a quest that ends with a different Bill. To get this call one npc Bill, (say) and the second one Bill' - the player probably won't notice the difference.
2. If you have two or three or more npc's - say Bill, Fred and George - you cannot have Fred give you a quest that ends with Bill and Bill give you a quest that ends with George and George give you a quest that ends with Fred. Your player will not be offered any quests at all.
Basically, an npc cannot be both a quest giver and a quest receiver - least ways I have not been able to make it happen.
You *can* have Fred give you a quest that ends with Bill and George give you a quest that ends with Fred - in which case Fred will not offer a quest until you have fulfilled George's.

The only way you can control the sequence that quests are offered/accepted is by having them given by the same npc.

Play with these rules and let me know if I've got it wrong or if there are even more restrictions. . .