Hi,
The field management links (e.g. edit and delete operations, widget and field type links) and the redirects to field related pages (e.g. "Save and Add Fields" on content type creation) all seem to be set as "//field..." rather than "/field...", causing it to fail when clicked or redirected. This also effects the links on the "Comment Fields" tab.
For example the Field Type link for a field called "field_policy_short_body" looks like: <a id="edit-fields-field-policy-short-body-type" class="ext" title="Edit field settings." href="//fields/field_policy_short_body/field-settings" target="_blank">Long text and summary</a>
If you save a form that should redirect to the field page, such as adding a new content type and selecting "Save and Fields", the redirect takes you to www.example.org/fields. However any changes made go through correctly and the content types are usable.
Oddly this issue is only affecting newly created content types and not the existing ones. The newly created content types also don't show up in the Views content type list, however they do show up for users when they go to add content.
I'm currently looking back through snapshot backups to try and locate when this became an issue, however the last update carried out was to 7.17.
I've disabled pathauto, sub-pathauto and global redirect to test whether those were having an effect on it, with no luck.
Caches are disabled and have been cleared out manually (including the APC cache).