Reasons for not praying behind an Imam: 1. Being a female Imam for a man: A woman's Imamate for a man is not valid and pure. The Prophet (peace and blessings of Allaah be upon him) said , " That nation will never succeed if it entrusts its work to a woman." (Bukhari , Tirmidhi , Sunan , Bayhaqi) The mushrik and deadly bid'ati imam: A person who associates any other creation with Allah in any act of worship , such as worshiping the tomb , going to the tomb , offering sijdah , nazar - niyaz , manat , qurbani , tawaf , etc. The one who claims the unseen and foretells the fate of the human hand or the fortune-teller , who (with the skin , bones , fur or feathers of any animal or bird , with the roots or flower-leaves of any plant , with any part of one's clothes , angels ) By writing the names of jinn , prophets , companions , saints or devils, or by making designs of different numbers , or by making various tricks of telesmati , by using dirty and unclean things (shirk tabiyya ) The prayers of this class of imams are not pure , the imamate is not pure and the prayers behind them are not pure. (Majallatul Buhusil Islamiyah: 19/159 , 22/72 , 24/6 , 69 , 26/98, 26/55) Accordingly, if a bid'at is muqaffirah or a bidat in which a person becomes a kaafir , then he is not behind the bid'at. 3. Imam who makes a mistake in reciting Qiraat: The prayer of a person who makes a mistake in reciting the Qur'an so that the meaning changes , his Imamate and the one who can recite a good Qur'an behind him is not pure. (Fatawa Ibn Uthaymeen 1/369 , Majallatul Buhusil Islamiyah: 20/146) Needless to say , the recitation of the Qur'an behind the wrong Qiraat is not pure. But the prayers of the impure reciters will be done. 4. The imamate of a person who is always suffering from urinary incontinence is not pure. (Fatawa Islamiyah , Saudi Ulama-Committee 1/396) 5. Imam of Ujuhin: If an Imam prays in an impure or ujuhin state, he should be followed. . Radio-TV Imam: It is not permissible for a man or a woman , healthy or sick , to follow his Imam in the obligatory or nafl , Jumu'ah or any other prayer of a mosque which is broadcast on the radio or TV without any excuse . Although their home is next to the mosque or in front , above or behind. In no case can a congregation be found by merely imitating words or words and pictures from a distance without appearing in the mosque. (Salatul Jamaati Hukmuha Aahkamuha , Dr. Saleh Sadlan 183 p.)