This recent Deedar thread brought to my memory some confusions which music companies and lovers entertain. Last year, HMV released a compilation which had Noor Jehan's pre-partition sonsg and they included a song by Laxmikant Pyarelal from a 1977 film which they claimed to be sung by Noor Jehan. Though, this other singer's name is also Noor Jehan she is a totally different personality and not the same as the legendary singer Malika-e-Tarannum Noor Jehan. Thsi other singer sang in fims like- Heer Ranjah(1970) and Sahab Bahadur(1973).
Similarly, there was a another Noor Jehan who worked as an actress in Ranjit Movietone films in 1930s and 40s and often her films are added to Noor Jehan's filmography.