Boost.Thread and fork

Hi, I have problem with boost.threads on linux ( under gcc ). I have a multithreaded aplication using Boost.Thread. It works just fine. However, I want to make a daemon out of it. So I tried to fork() at the start of the program and run all the relevant code ( including all threading ) in the child process. But when I do so, first call to create_thread hangs the process. I'm quite new to linux threading, so it is possible, that the problem is not related to Boost.Threads. Any hints? Thanks in advance. Pavol