If you are using shadows in views, care needs to be taken when using solid filled regions. The issue arises when solid filled regions are set to transparent. You may end up getting the following error “Shadows will not display if filled regions are set to foreground. Set filled regions to background". If you do get this message (some times you won’t) you will notice your shadows will not display or only partly display. The solution of course is “don’t use transparent solid filled regions in views you want to use shadows”. This issue is currently with Revit 2008 and it appears to be fixed in 2009.