bow cracks

[AkDan]

Ok, I'm ignorant when it comes to building so I just have to ask this.  Is a crack in the corner of the shelf (shelf and site window) on the back of a bow a common crack?  One that dives through the glass but not into the first wood lam?  Started under the back overlay and started popping it off (2 pieces due to the TD mechanism).
 

With my past history of cracked bows I'm a little worried, amongst other things.

[Tom Leemans]

I wouldn't say common but I would say fixable.