I've been working on my site today, and i've come to realise something.
You were indeed correct regarding search results when setting parameters inside query_posts.
The moment you start plonking any paramters into the query, you're over-writing the query string that has been passed into it by the search..
So as it stands (unless i'm mistaken), you cannot adjust the search results shown, you can however view more search results by using Prev/Next links as you would with regular entries.
So simply put, whatever you have set as "posts to show" (or whatever it's called in the admin) will be how many results you get on the search results (per page)...
Any adjustment to the query_posts line, will effectively re-write the query (losing the search paramters)...
NOTES: You can see the current search query in
get_query_vars('s'), and you'll soon see any adjustment to query_posts causes the data stored there to be lost..
There's also other info you can look at in get_query_vars, such as posts per page, and how many results were found in the search, etc.. (and various other bits).
Hope that clears things up a little, and i admit, i was indeed incorrect and a little fast to jump the gun before.. ;)