While doing a quick search here at the meta.discourse forums I noticed the search results included hits for the single letter A … is that normal, I thought the letter A is something not normally indexed in a search result.
I would have expected there to be more results too, if hits for A are normal.
Just curious, not a big deal 
Can you provide some specific steps to reproduce? I type “A” and “a” and then hit Enter in the search menu item but don’t get any results.
doh … I meant to include a screenshot sorry … here’s one.
This probably relates to “Stop Words” and full text searches
http://www.postgresql.org/docs/9.1/static/textsearch-dictionaries.html#TEXTSEARCH-STOPWORDS
This might be a bug in the search highlighting code, somehow.