In my travels last week looking for info regarding dead pixels on my 10D I did see a reference the situation you discribe. Can't find it now, however it mentioned dust under the IR filter on top of the chip causing this type of spotting you are seeing. I recall it was more apparent at small apatures than longer exposure. My limited expierence with bad pixels on monitors is they show up as pinpoints of bright white light. I'm seeing the same in the images from my camera (see my post from several days ago). Dosen't sound like a bad pixel to me but that is what I was asking about in my post. Maybe 2 is the magic number.
Stephen