Can't add contours to a surface

I'm not sure if installing the Service Pack 2 had anything to do with this but earlier this morning I created a surface in a drawing with no difficulties.  Around lunch I installed the service pack.  Since then I can create a surface but not add any contours to it.  They just don't show up.  It also will not allow me to delete any surfaces.  It says it's going to delete them but they never disappear.  I've tried rebooting a couple times but having the same issues.

Any thoughts?

Thanks for your help!!