Lars Peturs writes on his page:

"In the Swedish championships, the cubes were silicon treated, but they were not "broken in", so we only got about half out normal speed. I won with 40.43 sec..."

What does that mean, "broken in"?

well silicone spray has a tendancy to become sticky up to an hour after aplication, if you keep playing with it for a bit after you lube it, the lube 'breaks in' and activates, becoming fully slippy

I thought it would say more: http://dictionary.reference.com/search?q=broken%20in

Its an expression that is often used for shoes that have been worn enough to be really comfortable.

Most cubes need to be played with for a few hours at least (usually before they are first lubed) to wear down the "high spots" in the mechanism -- which may include small molding defects. I would call that process "breaking in".