Something is going wrong with city, state and zip fields...
$query = "INSERT into tbl_students (vb_id, username, student_fname, student_lname, student_gender, student_address1, student_address2, student_city, student_state, student_zip, student_email, student_dob, student_home_number, student_cell_number, student_work_number, student_dorm_number, student_organization) VALUES ".
"('{$bbuserinfo['userid']}','{$bbuserinfo['username']}','{$_POST['student_fname']}','{$_POST['student_lname']}','{$_POST['student_gender']}','{$_POST['student_address1']}',".
($_POST['student_address2'] == "" ? "NULL," : "'{$_POST['student_address2']}',") .
"'{$_POST['student_city']}','{$_POST['student_state']}','{$_POST['student_zip']}','{$bbuserinfo['email']}','{$_POST['student_dob']}','{$_POST['student_home_number']}','{$_POST['student_cell_number']}','{$_POST['student_work_number']}','{$_POST['student_dorm_number']}',".
($_POST['student_organization'] == "" ? "NULL," : "'{$_POST['student_organization']}',") ;