I'm having the same problem, but it is more annoying with Friends of the Republic as it is a story arc, and losing to Thana is such a pain. If it will help, here are the planet and quest details:
Taris
Planet story Arc
Quest Giver - General Farvin
Quest Name - Friends of the Republic
Bonus quest name - Declawing the Cathar – Thana Vesh is confident she can kill more Cathar warriors than you. Prove her wrong
(Well as this bonus never starts now you always LOSE the bet, and I hate to lose to her, also the mission drop box, is still next to General Farvin, question is...as it is a stage bonus quest, have they moved it or is it just bugged???)
But God would I wish they would fix it or address the problem.