Actually, I find the official wiki to be better - most of the top contributors moved to there. In this case - they both have the exact same information just formatted different and neither answers the guys question. I'm curious as to what you found in the unofficial one that you didn't in the official. At one time I would have said it is better to look up pre-nightfall information on the older one but that hasn't been the case for some time - the official one contains nearly everything the older one did and has better newer information (again, most of the top contributors moved to the new one).
In any case you need to follow the quest chain (the official is easy to find in the little box in the upper left of the page, the unofficial you will need to scroll towards the bottom to find it) and follow the quest chain to find
http://wiki.guildwars.com/wiki/Centaur_Blackmail. From there it is easy to note that Lonai gives you the quest and it is a primary one. We can also note that if he has completed this one (and would be able to find Zhed in his command post) then he should be at the follow up mission - Kodonur Crossroads.
My guess is that he either canceled Centaur Blackmail and needs to retake it from Lonai or isn't as far along as he thinks he is. In either case both Wikis have the same information but the official one is slightly easier to follow the quest chain.