Steady Concentration( Races of Stone, p. 144)
You are an expert at avoiding distractions and focusing your mind, and you can concentrate clearly even in the most stressful conditions.
Concentration 8 ranks,
You can always take 10 on Concentration checks, even when conditions would not normally allow you to do so.
A character cannot take 10 on any skill check if distracted or threatened, such as during combat.