I've got a member who has reported that a number of her PMs have gone missing. I've checked my stuff, and I don't notice anything particularly,
but it might be the kind of thing that you don't notice until you're looking for a specific message. Here's a link to her original description.
http://latenightchatter.y...pic/1992/master/1/?page=1
http://latenightchatter.y...pic/1992/master/1/?page=1

Only a few others were in any way distinctive, such as holiday greetings.