If you're not interested in the results of my previous posting about wireless cards then skip to the next bit. I finally bought two PCI cards via the link I mentioned. These were D-Link DWL-G520 revision B which has an Atheros chipset and after compiling and installing the Madwifi modules everything just works. The reason that they were cheap is probably because they appeared to be for the french market with all instructions in french. I didn't need the instructions or the CD so it wasn't a problem.
Right, back to smartd. First thanks to all for the useful imformation.
smartd is set up to run a short test every day and a long test once a week. I tried smartctl -l error which listed no errors and smartctl -H which said it passed the health test. So is there a problem or ain't there?
The hard drive is backed up every day so I'm not really worried about it.
What I find irritating is that the messages in my original post are injected into the logs every half-hour. As the saying goes 'I do not wish to know that' - well perhaps just the once.