(a) It is reported from all three, Ibn Jabir, Sa'id bin Abd al-Aziz and Abdullah bin al-Ala (may Allah have mercy on them), that Makhul (may Allah have mercy on him) used to say: Recite Surah al-Fatihah quietly in every rak'ah of the Maghrib, Isha and Fajr prayers.
(b) Makhul (may Allah have mercy on him) said: Recite Surah al-Fatihah quietly in those prayers in which the imam recites aloud, when the imam recites Surah al-Fatihah and falls silent; and if the imam does not fall silent, then recite Surah al-Fatihah before the imam, or along with the imam, or after him, at any time, but it is not right to leave it off in any situation.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2952