can't daemonize server with rails3

Hi folks

when I start 'rails server -e test' it runs perfect (there is a
process, I can find the server.pid file and run tests), but adding -d
to the start command just shows the start of the server and nothing
(no process, no pid file, no tests). And nothing in the logs to answer
this.
Same when I start rackup with -s webrick.
Someone out there able to run rails3 webrick daemonized?

thx in advance

Fritzek