Manage fields page keeps loading (not showing up)

Hi there,

I've started the day with a fresh Drupal install, install language and translate interface, installed a theme we've developed and started adding some taxonomy. After that I started building my first contenttype. I filled in the name and a new field name for the title field, put in the correct settings for the comments and publications options and i've clicked on save (add fields). After that the page just stays blank. I'm only seeing the overlay background without any content and nothing is happening.

The contenttype is saved but when i click on manage fields the same thing happends again. This applies only on my contenttype. I can manage fields on article and basic page without any problem.

Does somebody know what causes this problem??

Did a clean install and repeated the steps with no luck.
I'm on apache 2 and have a php limit of 512 mb which should be more then enough.

Tnx in advance!

--- update 1
Disabling the standard Drupal administration theme and the overlay module let's me get to the manage field page. How ever when i'm working on a view with the same contenttype i'm now getting an AJAX error:
A AJAX HTTP-request broke.
Path: /admin/structure/views/ajax/display/"view-name"/page/analyze-theme (or any other view function).

Readystate 4.

Any ideas?

--- update 2
Disabling javascript for the views ui let's me edit and save the view..