My WP doesn't create a feed

A few days ago, I made a mistake when I tried to create a second blog: I forgot to start a new database, so the database of my existing blog was overwritten. The problem was solved by installing a fresh database and uploading the backup file of my blog.

So far no problem – the blog works as it ever did. With one exception: It does no longer create a feed. Perhaps the system is still trying to read the old, destroyed database? Or have you any idea what the problem could be and how to solve it?