It seems like the in_array() function has been slightly altered in this (4.0.6) release compared to 4.0.3. 

A check of an array of chars against integers fail; but it didn't in verison 4.0.3. 

example:

$char_array = array("1","2","3");

if(in_array($char_array, 2))
   $output = "FOUND";
else
   $output = "NOT FOUND";

echo $output;


----> produces the output "NOT FOUND";

Seems some typecasting is necessary this time...