TYPO3 Core

seems the problem is around line 486
the patch changed line:

new Insertion.Bottom(insertObject, htmlData);

to
TYPO3.jQuery('#' + insertObject).append(htmlData);

and "insertObject" is sth like "data-52-tt_content-272-pi_flexform---data---sDEF---lDEF---settings.mediacenter---vDEF_records"
and YES, there is a div with this exact id (including the dot in the id)
the dot is comming from the field name "settings.mediacenter"

the problem is that the dot "." is interpreted differently between prototype and jquery.
prototype just passes it to "getElementById" so it's ok to have a dot.
But jquery thinks this dot is a class selector.

The solution:
Escape dot before passing it to the jquery.

Patch set 2 for branch master of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at http://review.typo3.org/33106

Patch set 3 for branch master of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at http://review.typo3.org/33106