Bug in AudioFileBuffer with different sample sizes?

hallo,
i'm using AudioFileBuffer from the max mxj api to read soundfiles
with varying sample sizes.
when i try to output the floating point data from the buf field, i
get correct results only for 16 bit files.
8 bit, 24 bit and 32 bit are all wrong, which to me looks like errors
in int-to-float-conversion.
do i overlook something here?
thanks, volker.

simple test class:

import com.cycling74.max.*;
import com.cycling74.msp.*;

public class test_afb extends MaxObject
{
    private AudioFileBuffer afb = null;

    public test_afb (Atom[] args) {
        declareInlets(new int[]{DataTypes.ALL});
        declareOutlets(new int[]{DataTypes.ALL});
    }

     /* load
soundfile----------------------------------------------------*/
     publicvoid open( String path ) {        
         String fname = MaxSystem.locateFile(path);
         post("filename: "+fname);

         try {
             afb = new AudioFileBuffer(fname);
             System.out.println("frame length: "+ afb.getFrameLength());
             System.out.println("samp size in bits: "+ afb.getSampleSizeInBits
());
             System.out.println("num channels: "+ afb.getChannels());
             System.out.println("big endian: "+ afb.isBigEndian());
             System.out.println("sample rate: "+ afb.getSampleRate());
         }
         catch(Exception e) {
             error("mxj test_afb: sorry, can't open that file!");
         }        
     }

     /* output sample value at index from channel 1-------------------*/
     publicvoid inlet (int index) {    
        outlet(0, afb.buf[0][index]);    
     }
}

simple test patch: