CSS positioning, again and again

Solving one problem, up comes another:

I have positioned one div with a picture 0 pixels away from the bottom line, but still theres a couple of pixels gap between the lower end of the picture and the border of my div.

It’s like this in IE, FF, Opera and Netscape, only of course with different witdth, so there’s no logic to it.
I checked the pictures; no gap in them.

The best example is on this page, but the problem goes for the entire site:


The contour of the map should be aligned with the line, but because of the magic gap it doesn’t.

Ideas, anyone?
PS: Sorry mac people, haven’t been able to test it on Safari yet :wink: