I solved Fantasy Quest and now I'm working on getting low score. (You know me.) Can anyone tell me what is the deal with the Unicorns?

After I give them what they want they are helpful. Sometimes they are helpful at least twice; sometimes they are helpful only once. Why are they so finiky?

My ideas so far are:
1) If you make too many moves(clicks) after you give them what they want, then (due to the passage of time) they forget you are their friend. If that is the case, does anyone know how many clicks causes them to become unhelpful again?

2) If you walk past them too many times, they get their feelings hurt. If that is the case, how many times can I walk past before they become unhelpful again?

3) If you have an item the don't like, they won't be helpful. If that's the case, then I guess I should figure it out for myself. So just tell me if this is the problem and I'll work on it.

4) Some other tricky thing the programer put in to drive us mad. In that case, any hints?

5) It was a bug but now it's a feature. Okay, sorry to suggest it, I'm sure it's not true.

Thanks, lelo

P.S. It's an awsome game. A little silly but I think that wikipedia is giving it a bad wrap.