I made, with DreamWeaver, a page with a few mouse-over's and swap images. Everything works fine, except in Google Chrome. I think there's something wrong with de css display (:block). It's quite complicated to explain, so here my link to the page. You can check the code than if you want to.
http://users.telenet.be/gepo/X_Tests/mouse_over.html
Purpose : When the black image disappears on mouse over, you see another image. It's a "colorpointer". On mouse over on a color, a frog in that color appears with the name.
In Chrome it's a war !