Hi Farrell and Tracy,
Thanks for writing. I've been able to reproduce this navigation issue and will report it to our developers.
Please note that if you select the Lexicon Category column heading about the list, you can get access to these categories.
Also note that you can also view the resulting messages under a given category by selecting that category under the "Lexicon" facets from the search results interface.
Thanks,
Josh Schneider
ePADD Community Manager