Totally broken content perhaps after object copy


We are experiencing weird error on pages, it looks like it appears after copy of some objects, placed in ATFolder.

We can see Contents and Interfaces tabs in the ZMI, but View tab shows random character mess like this:

kç¢N¥8ŸMzéA3?;‰ŽŽåÝQF8F¢WüP%‹IïA‘s’síŲ$=ª»I“sn*‡(œcÊŸT2ºÄdŸfÍ)‰WxË´È 'ŒëYVèáFDlc‘pòš-ÇZ'a‚Ó§•Æ²Bô}ô{M{™Ä(åèëGhôêøÈÝCùK’GIüJÓŽëq­·j„i’Ÿ"JÒIñeJØœÞC†W*d¬‡2%ª„”¼wz…q
‹*šöoÊÞiœ¤Dè(*öIìxäy£±‡cÀçÑÈ÷\gè‰ñàðȐè>„°4É‚âÜî€ìȏÝ04ÃhHÆd…#×EÑ(²œ Û7ƒ’&9¿

.... more X lines of this....

Looks like some uninitialized memory buffer or maybe
compressed data, I've tried to use linux file utility on it but without any
result. It is shown without tabs bar. Page rendering is longer than
usually. The same mess shows when we plainly view the object, also there is no
possibility to access Plone edit mode. Even after deletion of all objects
inside the folder the problem remains.

It can be related to translation mechanism (using Lingua
Plone) - at some point I thought that it is due to duplicities in translation
targets for original page. But it can be more complicated - we just have some
translated tree of documents and historical zodb restored from backup in a good
state, where everything looks good. If we delete all the subtree in the actual
zodb and import the zexp file exported from working instance, the problem is
instantly back. We packed the zodb manually after subtree deletion. No related
errors found inside logs.

Did anybody see something like this? Any help would be
appreciated. How we can debug something like this, when we can see no python
error we don't know where to start.

Zope Version: (2.13.21, python 2.7.5, linux2)
Plone 4.3.2 (4307)
CMF 2.2.7


Michal Samek