NoMemoryError: failed to allocate memory

Hi,     I'm using daemons to control a script that should always run on background in my development server. But, when I start the script it, returns this error:

<MissingSourceFile: no such file to load -- fast_xs> <NoMemoryError: failed to allocate memory> [...]

The script itself runs anyway, but failing to start threads (I use a threadpool with a low number of threads and I have a begin ... resume ... block that makes the script run anyway). Actually the thing is driving me crazy is that this error happens only when I "start" the daemon (e.g. ruby script/my_daemon start); everything is ok if instead of starting it I "run" it (e.g. ruby script/my_daemon run).

Any suggestion?