I am also having this issue in that I can not advance in the personal story quest for two of my characters. The only thing they have in common is that they both used the level 20 boost from the birthday gift and several tomes of knowledge.
One is an asura and one is a sylvari
The asura gets stuck when they are supposed to fight the incinerator golem except no golem appears
The sylvari gets stuck on trying to pick up the troll sap.
Reports filed and all that fun stuff.