Can't find key 1f137c9f in the strong set ; is it on the surfnet.nl keyserver ?
If not, please submit the key to the keyserver.
It will be propagated to many other keyservers, like pgp.mit.edu.
Get your key signed! Find someone with a key in the strong set
and cross-sign your key with that person's key. At www.biglumber.com
you can find lists of people worldwide, who are happy to sign your key.
the history of key 0x1f137c9f : msd and rank