Yeah, I was thinking there was something that Ninty had done in one of the early updates to stop browsing to local addresses, but I just remembered that it was nothing at all to do with that... it was before Opera was released and you could change the DNS of the Shop Channel to point to Google or goatse.cx or whatever.
Sorry, it's been a long week.
As for DivX, it's not compatible... you have to re-encode to FLV instead. Hopefully Ninty will change this at some stage.