Hello! I am currently observing a strange crash on my test systems. The core file tells me that it happens when constructing a regular expression from a string for the first time. We are using boost 1.33.1. Please find below some system details. Configuration no. 1 is the current stable workung one. In configuration no. 2 my program crashes in the constructor of boost::regex. The crash seems to be caused by some threading related functions, but the application is single threaded. The call stack is attached to this e-mail. In configuration no. 3 my program does not crash, but hangs at nearly the same position inside the boost::regex constructor. Again inside some threading related functions of my single threaded application. It is related to my system configuration. Here are the ones I use: 1. This configuration works since years * Compilation of libboost_regex: SunOS 5.8 Generic_117350-35 sun4u sparc SUNW,Sun-Blade-2500 CC: Sun WorkShop 6 update 2 C++ 5.3 Patch 111685-24 2006/11/03 * Compilation of my application SunOS 5.8 Generic_117350-35 sun4u sparc SUNW,Sun-Blade-2500 CC: Sun WorkShop 6 update 2 C++ 5.3 Patch 111685-24 2006/11/03 * Execution environment SunOS 5.8 Generic_117350-35 sun4u sparc SUNW,Sun-Fire-V240 2. We are noe migrating to Solaris 10. This is causing problems. First we just change the execution environment: * Execution environment SunOS 5.10 Generic_141444-09 sun4u sparc SUNW,Sun-Fire-V210 3. Then we also change the compilation environment: * Compilation of libboost_regex is not changed. Libraries have not even been re-compiled. * Compilation of my application SunOS 5.10 Generic_141414-01 sun4u sparc SUNW,SPARC-Enterprise CC: Sun WorkShop 6 update 2 C++ 5.3 Patch 111685-24 2006/11/03 * Execution environment SunOS 5.10 Generic_141444-09 sun4u sparc SUNW,Sun-Fire-V210 I cannot change these configurations. But I would have the chance to move to a newer version of boost if it would compile with my legacy compiler (which it doesn't). Please help me solving this problem! Thanks in advance! With best regards, Thomas