DNS Problem - http://host/?dl=1

[Vinicius Massuchetto <viniciusandre@gmail.com>]

Hi!

It's a really strange problem, and my network skills are not the best 
ones. Sometimes when I'm browsing something it suddenly redirects me to 
/?dl=1 of where I am.

That gives me an annoying message: The document you requested was not 
found. May we suggest our home page?

Sometimes apt, Icedove and other web apps don't connect too.

The same happens in an Ubuntu on the same network, but not on the 
Windows boxes. I don't know if it's the router or the network settings.

Thanks!
Vinicius