I can't help but notice the irony of the fact that River5 does not handle elegantly title-less blog posts. I think that River5 ought to have a "click here" title for title-less blog posts so that a reader knows to click to see what is written. Or perhaps River5 ought to not grab title-less blog posts?
Frank, just noticed your post on the 1999 blog. I don't know that it is River5 that has the problem, I think it is the river display app code that Dave Winer has provided that decides to present the material the way it does (like on my river site). I have this on my to-do list to investigate, but I appreciate your mentioning it again.
If for title-less posts the content was displayed in the stream, with links to posts with titles, I think you would end up with something that looked a bit like Twitter.