Hi! I have tracked down the problem with Collector issue 517 (Unicode problems) now: My Product used a modified manage_page_header that did not set the meta header for the encoding. After copying the relevant lines from the new manage_page_header in Zope 2.6 everything works fine, except for one remaining issue: One can create properties with Umlauts or other non-ASCII characters (which probably should be forbidden in general). While in 2.5.1 it is possible to delete such properties again, 2.6b1 will throw an error: The property [...] does not exist Probably the lookup in the property dictionary does not use the right encoding. I am not sure if that breaks old code, but the best way of getting rid of that problem might be to catch the creation of non-ASCII property names and don't let people use them. Cheers Joachim