[QUOTE=scande;18869]
I added 20 new products 2-3 days ago.[/QUOTE]
I think this can definitely not be the problem
[QUOTE=scande;18869]
To make sure no changes in the code could be the problem I copied the database to a clean install of oxid e-sales - and got the same result.[/QUOTE]
Very good! What I would do next is to check the complete system on another server the exclude a problem of the server environment. If the problem still appears - obviously something in your database was damaged.