NoClassDefFound exception when using jcifs library on Android 2.3

I am using jcifs-1.3.17.jar library in my android application.

The following part of the code works well on the android 1.6 simulator, but does not work on 2.3 and 3.0.

Follow the warning in the logcat 2.3 simulator when starting the application.

05-03 10:41:43.105: E/dalvikvm(338): Could not find class 'jcifs.smb.NtlmPasswordAuthentication', referenced from method myPackage.getFile

And get the following exception when creating the NtlmPasswordAuthentication object.

05-03 10:49:59.765: E/AndroidRuntime(338): java.lang.NoClassDefFoundError: jcifs.smb.NtlmPasswordAuthentication

Can anyone say what I'm missing?

My function

public boolean getFile(String url) 
    {
        try 
        {

            String  name="server1";//my windows username
            String  password="password1";//my windows password

            SmbFile dir=null;
            url = url.toLowerCase();

            if (!url.startsWith("smb://") )
                url = "smb://" + url;

            SmbFile file = null;
            try 
            {
                NtlmPasswordAuthentication auth = new NtlmPasswordAuthentication(null, name, password);
                file = new SmbFile(url, auth);
                SmbFileInputStream in = new SmbFileInputStream( file );

                File gpxfile = null;
                File root = Environment.getExternalStorageDirectory();
                gpxfile = new File(root, file.getName());
                gpxfile.delete();
                gpxfile.createNewFile();
                FileOutputStream out = new FileOutputStream(gpxfile);

                long t0 = System.currentTimeMillis();

                byte[] b = new byte[8192];
                int n, tot = 0;
                long t1 = t0;
                while(( n = in.read( b )) > 0 ) {
                    out.write( b, 0, n );
                    tot += n;
                }


            } 
            catch (Exception e1) 
            {

            }


            return true;
        } 
        catch (Exception e) 
        {
            return false;
        }
    }