well for starters, I'd clear out the internet history and temp files. Also have you got the update yet?
here is what I've noticed though, if I search on a name, like Kate Middleton it DOES jump straight to images, however if I search on a term like RIM (Blackberry) it jumps to local scout :/ If I search on RIMM (the stock symbol) it jumps to web and shows me a stock quote. So I think it all has to do with the context of the search and possibly what you are seaeching on every time just so happens to jump to the images because it thinks that's the most likely context of your search.
search on something very obscure and see if that also jumps to images.
I guess I've never paid much attention to this because it has always jumped to the most relevant page for me based on what I'm searching :)
I wish I could set this. I'd prefer the "web" results to show each time it's the lowest bandwidth! I guess there's some algorithm that determines which page shows as the default. For example a search for:
Beckham > Images
Sauce > Web
Pizza > Local
My quick unscientific research shows that a search for a person shows "Images" a search for a commonly purchased item show "Local" and a search for a generic term shows "Web".