[Xorith]

if ($itemcount{13758} && $itemcount{20270} && $itemcount{6011} && $itemcount{20290} == 1)

Try this:

if( $item1 == 13758 && 
    $item2 == 20270 &&
    $item3 == 6011 &&
    $item4 == 20290 )

I also refer you to this:
http://www.eqemulator.net/forums/viewtopic.php?t=12020
-- Xorith