[TYPO3-ttnews] List view showing wrong (old) articles

[Frank Sonck]

Hello people,

I have this strange problem on our site: of all the pages where I have a 
tt_news list view plugin there are some pages where this list view gives 
on a frequent basis an old set of articles. It shows for example articles 
starting from 2008. I refresh the page and I get articles from 2009. I 
refresh the page cache (in BE) and all is ok. But some minutes later the 
problem is back. 
I'm using TYPO3 v4.4.6 and tt_news 3.0.1.

Does anyone know what could cause this problem?

Kind greetings,

Frank Sonck