lol, it took me a bit to figure out what was happening too.

Try this one...It returns 1's. It is seeing the first empty element as a find, and then exiting.

 Code:
$startingdates = "test","","2011/08/01","2011/08/08"

$check = "2011/08/08"
? "AScan result: "+AScan($startingdates,$check,,,1)

$check = "poop"
? "AScan result: "+AScan($startingdates,$check,,,1)

get $