ping problem

Hi,

I have a problem with the ping services. It seems that ping doesn’t work. I entered a list of ping services that I found on the web but whenever I publish a post there is no ping going out, at least that’s how it seems. When I search for a post in one of the ping services, like technorati for example, I can never find it.

Is there some requirement that my webhoster maybe fails to offer?
I looked in the database and see that the field to_ping in the table wp_posts is empty. I don’t quite understand the mechanism but from the name of the column I would expect this field to have a value.

If somebody could help me, it would be greatly appreciated.

best regards to the wordpress community,
Pierre