What Audio File Formats Work on MPC2500

I had some samples that i wanted to put on the mpc. I converted the Flac files into wav using WavePad. When i then transferred these onto my mpc and pressed the PLAY option or LOAD option a dialogue box appeared saying "WRONG FILE". I then converted the same flac files to wav using ABLETON and transferred them onto the MPC. They worked fine. So my question is, exactly what file types work on the mpc2500.

this is covered in the manual...

but WAV files need to be 16bit and 44100Hz. you're probably saving them as 24bit or something when they give you the error.