I also noticed this happening when I too used the Anvil program to edit some of the midi files. It depends on what instrument you’re trying to add. If it’s anywhere in the upper scale of the instruments such as cymbals or cowbells or some of the bongos or something like that, it will not reproduce these instruments when you import them back to the Beat Buddy or BB Manager. I noticed this happening with other midi editors as well. Most of the time it will reproduce the snare and tom-toms or most of the lower numbers of instruments in the midi files but not a lot of the others in the higher numbers. Don’t know why except it might be a proprietary thing or there might be a confliction with the numbers assigned to the different midi instruments. This also happens when you shift the starting of the notes in the particular measure. It takes the whole phrase away and sometimes stalls the Beat Buddy in it’s tracks especially in the BB Manager. You then have to completely back out of the program and start over. A real pain sometimes. This is one of those times you scratch your head wondering, but it’s not likely you’ll find the answer. It just happens that way and you have to go from there. Sorry not to be any great help here. Unfortunately, if noone else has Anvil, they cannot help you either. You may have to contact Anvil to get the answers. The support team will probably give you the same answer unless one of them has had a similar situation and used Anvil.