Assignment

The $file and the $name optional_params did not.  I had to manually code in the directory using the $filearea object and the $name param inorder to obtain the correct file path and file name so that I could use fulldelete() to remove the file(s).

Here is an example of what I had to do.
ex:

$filearea = $this->file_area_name($userid);

//path where AU assignment is located
$filepath = "$CFG->dataroot/$filearea/$name";
.
.
.
fulldelete($filepath);

This solved my problem in moodle 1.6 beta 5.