No ping from update services

I’m running a blog and pinging a couple of different portals using the Update Services interface.

I have put the portals ping-links on seperate lines in Update Services.

The portals are not pinged when i post a new post and i don’t see any errors in any logs.

Is there any settings at the hosts that could be blocking this feature? Is there any easy way to test for such blocking with a custom php-file for example?

Thanks in advance
Leif Ershag