Does anyone else ever have this problem with component transparency in an assembly?

Is this a display/graphics issue, or something else?

Actually, the picture above is a multi-body part, but it happens in assemblies too.  Some surfaces show up as non-transparent, while most do not.  It does not seem random--I can close and open again with the same problem.

It's not a huge inconvenience, just annoying.  If anyone has an answer I would be appreciative.