.hover is not working correctly..

.hover is not working correctly..

  1. $j('div.LeftNavArrowRt').parent().hover(
  2. function() {
  3. var selector = ".sub_" + $j(this).attr('id');
  4. $j(selector).css('top', $j(this).position().top).animate( {
  5. width : 'show'
  6. });
  7. }, 
  8. function() {
  9. $j(".sub_" + $j(this).attr('id')).hide();
  10. });
I am using jquery for my vertical hover menu, but the menus don't behave consitently and somtimes hide on hover out and sometime don't. 
In the code above I select parent divs of the divs that have an right pointing arrow

j('div.LeftNavArrowRt').parent()
and call hover with hover in selecting a div that corresponds to flyout submenu, sets its top position to correspond with its parent and animate show.
on hover out i just hide it.

Can some one tell me what I am doing wrong?