Deleting custom content types: caching issue

When I delete a custom content type made with CCK, it is not removed from the "Create content" menu (there still is a link to that content type, the link just doesn't work). It thus appears that the content type is deleted alright, but a reference to it is left in the 'Create content' menu. Only switching the CCK module off and on in "Administer > Modules" causes that empty reference to go away.