I'm guessing that the filenames exceed the 16 character limit and the files you're loading may be over 16 characters. The problem is that if they are over 16 characters long and the first 16 characters are identical, they will all sound the same as the original file you loaded. If that's the case, the easist method to correct it would be to rename those files in your computer, since it's faster. You can either shorten the name or you can simply add a number in front of each file. I'll demonstrate an example below...
Roland TR-909 BD 1
Roland TR-909 BD 2
Roland TR-909 BD 3
Now each of the files above are different, but the first 16 characters are identical. When you audition the first file, then scroll down to the next on your MPC, it'll play the first file instead. Heres how you can correct this problem...
TR-909 BD 1
TR-909 BD 2
TR-909 BD 3
Now lets say you have over 100 kick drums. It would take a long time to rename all of them. This is where the number prefix works well.
EXAMPLE:
001 Roland TR-909 BD 1
002 Roland TR-909 BD 2
003 Roland TR-909 BD 3
Now ofcourse there arent that many bass drum variations in a 909 kit, but I'm just using it as an example of what you can do. You may find a few samples uploaded here like the "300 Breaks" zip file. Now since there's a few identical filenames over the 16 character limit, that's where I found adding the prefix number in the example above more useful than changing the entire filename, since it's quicker and I still have a descriptive reference of the filename.
In small drum kits like the Roland kits for example, shortening the filename by removing the spaces in between characters can help since a space is actually counted as 1 character. So you can quickly edit the filename like so...
RolandTR-909BD1
RolandTR-909BD2
RolandTR-909BD3
Now all the filenames above are less than 16 characters and will audition and load properly in your MPC.
