RAF and Quests - the bonus Exp is not always applied?

Hi,
I started my way to wonderfull world of dual-boxing today. And the joyrney has been quite smooth so far for my pala-Priest combo. However i noticed that my paladin was getting ahead in experience. While i first thought it was just because of experience gained form mobs, I changed my mind when it got so bad that Paladin was one level ahead even though i had done some quests with priest which I had not done with the pala. When i investicated the issue i found that the priest did not always reseave the "refer-a-friend" bonus from quest returnings. Has anyone else come across this problem?
some random information:
* it does not happen with every quest, so far i have seen two occations ( that i have noticed).
* Paladins account is the Veteran one.
* experience from mobs gets the bonus everytime.

I had this happen a few times. The cause was I would hand in a quest on the main, and he would level. This then made the quest (if he still had it) gray level. Because of that it was considered gray to the rest of the group and they would not get the RAF bonus on turn in. So if your main out levels the quest, the rest don't get the bonus.

Time to move on to the next area and get higher level quests!

Thanks for answering, I have to keep that in mind. :)

other thing which i did and had to juggle was using account bound shoulders