LinuxQuestions.org - strange file creation problem

Hey all,
I'm trying to do some manipulation to bitmaps, which works fine, but when i try to export the created bitmap to disk, say to file morph000.bmp the file created will be morph000.bmpi? (including the questionmark) I'm really not sure what causes this error.
any ideas are appreciated.
Thanks!
-JSS

Code:

    if (disk_save)  {

      filename = (char*)malloc(10*sizeof(char));

      sprintf(filename,"morph%03d.bmp", t);

      SaveDIBitmap(filename, Bitmap1Info,  buffer[t]);

    }

SaveDIBitmap()

Code:

 if ((fp = fopen(filename, "wb")) == NULL)

        return (-1);

  ...

  fclose(fp)