Render Shadow issues

Hi, I’m having some render issues with the sun casting shadows. In render mode, my buildings aren’t casting shadows the way they were just a few days ago. All of my objects are set to cast shadows:

and these are my render options:

There still seem to be some very fuzzy shadows cast against the ground plane, and roofs, etc. seem to shade.

I thought maybe my model was oriented in a weird way, but then I tried a ray-traced render, and all the shadows appeared exactly where I expected them. What could be causing ray-tracing to cast shadows and the regular rhino renderer not to?

Thanks in advance!

A couple of screen grabs to show the actual difference in the scene would probably be helpful as well.

render files are duper hard to diagnose without a file, or some screen shots.