Deeper Nesting Levels for suckerfish menus

Theoretically, yes, but it will require adding CSS for all the additional levels. You might try copying the CSS for the second level lists from navigation.css into your local.css and then adding the appropriate extra ul or li to each item to extend it an additional level and see what happens:

/* SECOND LEVEL LISTS */

#suckerfishmenu ul.menu ul {
  padding: 0;
  margin: 0;
  list-style: none;
  border-top: 1px solid #fff;
}

#suckerfishmenu ul.menu li ul {
  position: absolute;
  width: 200px;
  left: -999em; /* to hide menus */
}

#suckerfishmenu ul.menu li li {
  /* height: auto; */
  float: left;
  width: 200px;
}

#suckerfishmenu ul.menu li li a:link,
#suckerfishmenu ul.menu li li a:visited {
  width: 170px;
}

#suckerfishmenu ul.menu li ul a {
  width: 200px;
  line-height: 24px;
  font-weight: bold;
  font-size: 95%;
  border: 1px solid #fff;
  border-top: none;
}

/* margin for pullouts */
#suckerfishmenu ul.menu li ul ul {
  margin: -25px 0px 0px 199px;
}

#suckerfishmenu ul.menu li:hover ul ul, 
#suckerfishmenu ul.menu li:hover ul ul ul, 
#suckerfishmenu ul.menu li.sfhover ul ul, 
#suckerfishmenu ul.menu li.sfhover ul ul ul {
  left: -999em;
}

#suckerfishmenu ul.menu li:hover ul, 
#suckerfishmenu ul.menu li li:hover ul, 
#suckerfishmenu ul.menu li li li:hover ul, 
#suckerfishmenu ul.menu li.sfhover ul, 
#suckerfishmenu ul.menu li li.sfhover ul, 
#suckerfishmenu ul.menu li li li.sfhover ul {
  left: auto;
}

If you have problems, let me know and I'll try to help.

Closing due to inactivity.