ooh, that's strange...
i say it's strange because they should have transparent backgrounds and not grey. lol
what browser are you running (i can;t quite tell) - it seems that it's not recognising the transparencies in the PNG images.
do you have a different browser to try it?
to give you a hint it should look like this:
http://www.b-jarvis.co.uk/images/wiireg.JPG