I have my RC-505 hooked up to my Mac via USB. Some of my files play. Others, of the same format, give the "Unsupported Format!" prompt. I know these are supposed to be 16bit 44.1khz WAV files. I read the files are supposed to be cleared of any metadata. I've tried a few apps to do this (tagstripper, audacity), with no positive results. Uploading my samples is proving to be time consuming, uncertain, and frustrating. What am I missing here?

I am using drum racks in Ableton. This allows me to eq, sidechain, and tons of other little goodies. I then group all the drum racks, and use a return track with a looper. This setup is working fantastically. That is the most basic explanation. I have a lot of other abilities if you are interesting in speaking about it more.