Adding keyservers in PGP desktop

Hello,

I would like to add keyservers to PGP desktop. For instance the server: pgp.mit.edu: What kind of "type", "address", "port" and "base dn" do I have to enter for this server? The thing is I can browse directly to the website of the keyserver and I am able to retrieve uploaded key data. But for some reason I cannot retrieve keys from this server using the search function of PGP Desktop. I tried this with several servers and several configurations.

Some hints are highly appreciated.

Cheers