<PRE-SCRIPT (as opposed to post-script :): I registered here today just so I could talk about this subject. Please do not hold this against me (being a scoop site newbie).>
When I normally browse a site, I will go over the story listing, opening up a screen for each that interests me. I then read through the stories and comments, possibly moderating, story voting or poll voting along the way. When I go to submit those votes, I am brought back to the same story I was reading before. This has the effect of resetting the viewed_stories waterline. In order to not miss the comments that were submitted while I was reading, I have to read them immediately, because that is the last time I will see them as new.
I think a good solution to this problem is to have a user configurable option for the action taken when submitting moderations, story votes, poll votes or a combination of the above. Some of the destinations could be: same story, same section, front page, all stories or your comments.
Another issue I have just due to the way I read is that I will read stories from home and work. With large stories, I may open it up at work, but not finish it. I often want to pick up where I left off at work, but that is usually not possible without reading all of the comments again (I do not have an encyclopedic memory :). One possible solution would be to keep track of the steps that you took ("read to message 40", "read to message 71", etc...). This would probably be very annoying to code and I wouldn't press for this feature, but call it a "cool to have"
Thanks for your time.
<Post script: this is my first scoop story anywhere>