[TYPO3-ttnews] First Category of list automatically added to news item on edit

[Pieter]

Hello,

the first category shown in the list of categories (= the category with 
uid=1) is added to each news item if I edit the item.  I have to remove 
this category each time again.

Configuration:
- Typo3 4.0
- tt_news 2.2.24 (or 2.2.42)
- "Modern Template building" type of site

This seems to be a 4.0 problem.  The new reference system in Typo3 4.0 
shows a reference to this category for each news record.  But that 
category is only used in some news records...

Never had this problem when running 3.8.1.

Can anyone confirm this?

A also have an error message in the "DB Check" module "Update reference 
index" screen when I press "Update now" or "Check now":
Warning: array_unique(): The argument should be an array in 
<sitepath>/site/typo3_src-4.0/t3lib/class.t3lib_flexformtools.php on 
line 150

Anyone having this error?  And can it be related to the problem?

I did a database compare, cleaned the cache.

Regards,
Pieter