Hello, The Boost.Signals FAQ says that Boost.Signals is not thread safe. Are there thread safety problems even when two different threads use the Signals library, but no slots, connections, or signals are shared between those threads? Best regards, Richard Peters This message and attachment(s) are intended solely for the use of the addressee and may contain information that is privileged, confidential or otherwise exempt from disclosure under applicable law. If you are not the intended recipient or agent thereof responsible for delivering this message to the intended recipient, you are hereby notified that any dissemination, distribution, or copying of this communication is strictly prohibited. If you have received this communication in error, please notify the sender immediately by telephone and with a "reply" message. Thank you for your cooperation.