[FLOW3-general] Problem with registration of DateTime Object

[Jan Grubenbecher]

Hi,
I have a problem, with the Blog-Extension. I tried to create a new Post
but get the following Exception:
#1265367590: Object "DateTime" is not registered. (More information)

F3\FLOW3\Object\Exception\UnknownObjectException thrown in file
Packages/Framework/FLOW3/Classes/Object/Container/AbstractObjectContainer.php
in line 267.

I tried it a my local machine and also at mittwald. Both show the same
error. Do I have to register Standard PHP classes too? Or can I
configure FLOW3 to do it for me?
Kind regards

--
Jan Grubenbecher