WordPress.org dashboard layout problems when using a local MAMP server

Dear,

I have currently configured a local MAMP server on my iMAC. Hence when entering and bypassing the username & password @ localhost:8888/woordaccent/wordpress/wp-login.php my final WordPress dashboard layout has been screwed up. You can compare it with a text based design layout. Off course, it’s impossible to continue in such a way. Perhaps someone did have similar problems in the past, and knows how to solve such a behaviour?

Info:
OS: Mountain Lion
MAMP server: 2.1.1
My first online WordPress.com attempt: marc.rammant.wordpress.com

Now I would like to create a wordpress.org site.
Goal: customising my site layout, adding plugins, …

Thanks in advance for your help.
MRT