Geoffrey, in case you don't check the blogosphere reader, I published some numbers here: You are not allowed to view links. Register or Login to view.

Removing [y] takes h2 from barely over 3 to 3.20, which is a huge increase. However, as Nick also said, entropy is not useful for detecting nulls. Moreover, while h1 and h2 are now perfectly normal, many other stats are not...

Marco noticed a mistake in my calculations. The value I got by combining glyphs is:
h1 = 4.05
h2 = 2.86

When additionally [y] is removed, 
h1 = 3.99
h2 = 3.02

Since the data in my original post are now off by quite a bit, I will publish a correction later this week.