Using Rasika Sruthi Box, when you play Madhayma Sruthi (by pulling down the volume of 'pa' and pushing up the volume of 'ma'), you here Madhyama Sruthi all right. But when yuu stop the sound and start it again, only 'sa' and 'Sa' are heard and 'ma' is not heard.

To resolve this, while the sound is on, click on the the 'ma' scroll bar thumb (see the picture below) and you will hear the 'ma' note. (Revised srbox6.exe file will be shortly made available for downloading.)