The Mage Class Quest “Hidden Secrets” cannot be completed on my level 32 Blood Elf Mage. the quest is granted by Tabetha in Dustwallow Marsh and is meant to be completed at The Shimmering Flats in Thousand Needles but the NPC Magus Tirth has a grey question mark above his head and the quest dialog box for Hidden Secrets is blank with no option to complete.
I have the same problem, the weird thing was that a mage next to me was doing the quest.
as some one who really only is playing to re-live my mage i created during original BC not being able to do this mage quest is a real swift kick in the nuts