An imaam who has a problem with pronunciation
Question

                The imam of our masjid have problems pronouncing many of the arabic words while reciting the Qur'an. I was told that of the imam can't recite the Qur'an, pronounce the arabic words as good or better than you do you can't pray behind him lest your prayer is invalid. When I heard this I stopped praying behind this imam but have not said anything to him yet. Can you please calrify this matter for me.
Praise be to Allah. 
          If the imaam is unable to pronounce some words because he is a foreigner 
          (non-Arab), for example, or because he has an accent, then it is OK 
          for him to lead others like him in prayer.  If there is no one 
          who can pronounce the words properly, then his leading them in prayer 
          is valid and the prayers offered behind him are valid. But if there 
          is someone who can pronounce all the words properly, in that case it 
          is not correct for someone like the imaam mentioned in the question 
          to lead the prayer.