Maybe an "alpha" is needed before the "beta" next time..

Do the following search:

keyword: american
Find threads with: at least 0 replies (the default setting)
Find posts from: your last visit
sort results by: last posting date in descending order
Show results as: posts

I did that search and I saw a post on the first page from 2001, in the subsequent pages I saw posts from 2005, 2007, 2008...get the idea? clearly wrong.

I only last logged in last week. Please fix it. All I want to do is see what posts have been made with a given keyword since I last logged in. Why is that so hard?

What the system appears to be doing is that there may be a post in a thread that may be years old, but if the thread has been posted to within the given timeframe, it thinks it should return that post, which is not what I'm asking for. The last verison of search had no problem doing this.