This could well be an intended change rather than an actual bug, but when tokenizing an array or an array coerced into a string, such as when storing an array as an ATTR and having it synced to the client, this results in an extra empty entry within the created array:
PHP Code:
//both Echo 2, whereas V5 Echo's 1
temp.a = {"test"};
echo(temp.a.tokenize().size());
temp.a = "test,";
echo(temp.a.tokenize().size());
This was causing a problem with Classic's spar arena system where the V6 client would think there are 2 players within an arena rather than 1.