I ran into some issues with the search features and then tried them on reeftalk to confirm.
Here is what I noted:
1. With all cookies cleared, the first search from the top level works on a known keyword. (I noticed that the search function is set to call the advanced search page without submitting a form on reeftalk, but I am not sure if that is the way it is supposed to work. I would presume if a value is entered into the search field that the search should execute upon clicking submit and not call the advanced search page.
2. If you click on any of the pre-defined queries, i.e. Last Day, Last 7 Days, etc, and in both cases these come up with no results, any further queries, even after returning to the top level returns no results. This would be in contrast from the results returned from the same query in #1 above. The only way I've found to fix this is log out and clear cookies (if that helps).
Hopefully I'm not all wet on this and am reporting something of value to you!