They aren't ever cached. The newest Super Search searches the live database directly. You can find anything no matter how recently it was added or changed.
Ok, I figured out what my problem was. Super Search will return results for things that are listed as comments in the HTML. Then I wouldn't see that text on the page and thought it was searching a cached version of the User pages. If I had actually taken the time to view the source before I would have realized this a while ago.
Heh. I had the same problem. In testing, I searched for \\% and it found nodes containing \%. I eventually tracked this down to a bug in MySQL. To match \\ in a string in MySQL you have to say LIKE '%\\\\\\\\%' and I was only saying LIKE '%\\\\%'. Weird.
Anyway, after I put the patch in to work around it I searched for \\% again and the first match I clicked on was a node that contained \% but no \\%. I scratched my head for a while on that until I decided to "view source" and search through that. (: