Improved Concentration Aura-bug confirmed
Gamemaster on the EU WoW forums posted a list of known issues, among it was one regarding Improved Concentration Aura:
Paladins:Phew! I'm happy I saved those last three points! I was about to use them for another talent...
Improved Concentration Aura (Talent):
Interrupting spells with silencing components, such as Improved Kick or Shield Bash seem to behave inappropriately with the Paladin talent "Improved Concentration Aura".
We will be correcting this as soon as possible.