Hi, thanks for the reply.
My pc is on the top floor too, but wired (gigabit) to the router downstairs. The router is right under the bedroom. I have no phones (just mobile phones).
I've just now installed inSIDDer and switched to an unused channel, so I will be testing it in a few moments when I go to bed

Oh, I also redirected two antennes to the sides. I had read that where the antenna's are pointing to the signal is the weakest!
Ah, I have firmware 1.31EUb2. I had 1.11EU before yesterday. I will be doing some tests now to see if something changed for the better.
Oh btw, the connection speed is indicated as 130 right beside the router.