So then everyone else's text doesn't wrap right after that post.

That's just HTML, and, as you say, could be fixed by putting each message in its own table. But there's also a separate bug (at least in IE6) whereby sometimes the next line of a post isn't wrapped but the table cell and table aren't widened for it either and the tail end of the line just isn't visible, even with the window's horizontal scroll bar at maximum.

Peter (with poor tolerance for bad table layout algorithms)