For searching the old 'solved cases' database: take a look at Brett's writeup @ How to search the old Sybase Infobase "Solved Cases" knowledgebase
The obvious(?) downside is that the 'solved cases' database is not being updated with new cases so we're left with the KBA/notes database where, as you've found, search success relies heavily on luck and sacrificing a few farm animals.
It's too bad the KBA/notes are hidden from public view (ie, requires a Marketplace login to access) else a google search would likely be easier/quicker than using scn's search engine. (If I'm trying to find a post in the scn forums I skip the crappy scn search engine and go straight to google.com ... works great every time!)