Contacting SMC support reached, I believe, all the way to India if you can imagine that. Tried both email support and then phone support. Procedures proposed don't even agree with each other so I was very leary of going too far with either one. Phone support had me re-scan within card manager multiple times with no outcome at all. Email support started by telling me to uninstall all my software programs. Since I would not know how to re-install them, I stopped at the beginning of this list of things to do.
Is there a simple answer to this problem? Is it time to replace the wireless card, perhaps? Where do people go for help who just don't have any real knowledge or expertise in computers? Electric typewriters were just coming into their own when I went to high school. So, help in very basic terms would be much appreciated!