Ok, here is a tinypic for the same picture as the one in imageshack
The house has recently been "done up" to sell, so yes they are new
windows. They have "brick arch" lintels on the outside (probably
large timber lintel on the inside) it looks like the brick arch is
starting to give way.
So it would probably require new lintels to the outside replacing the
brick arches. Not a big job eh?
The other house, I don't have an actual pic of the house so I'll use
this pic of a house, In this house the windows are all old and the
house has been rendered, and the area in green is where the render has
been recently renewed, the red marks are where the cracks are. The
crack (on the left) now runs along the line of new rendering.
So again this is indicative of failing lintels?