I suppose it doesn't happen to all of them, and that's the sticky point...if you can't show visual or electronic evidence of the problem, then technically, you don't have the problem. I don't know how fast it can go from OK to bad, though.

Oh well...if you don't have it, you don't have it. Don't sit around and fret over it. It'd be like sitting and worrying you had cancer when there's nothing that suggests you do.

"Think of it, if you like, as a librarian with a G-string under the tweed." Clarkson on the Mondeo.