Pre-caching, it looks at the domain names in the links and requests a lookup before you click on them so you don't have to wait for the name to resolve before connecting to the server.
Oh I see. Still, I haven't personally noticed a speed difference so my PC / ISP's DNS server must be quick enough already.

it did load in a flash for me in FF2 but evidently something changed.

when thats fixed i can go back to using it normally 