Showme,one other thing to check.
IF you remove the offending glass,check where the crack starts from,a badly ground edge with any nicks can create stress risers and subsequent cracking even if everything's correct inside the door,a heavily shut/slammed door could be sufficient to cause failure.
It's entirely possible the glass was supplied with a small defect.


1950 Chevy Advance Design 3100 in Scotland
In the Stovebolt Gallery
More pix on Flickr.
I've definately got this truck thing in my blood ... my DNA sequence has torque settings
"Of all the small nations of this earth,perhaps only the ancient Greeks surpass the Scots in their contribution to mankind" Winston Churchill.