Hi I am running boost 1.31.1 on Fedora Core 6 with gcc 4.1.1 I get the following error when using boost::regex: Program received signal SIGSEGV, Segmentation fault. 0x0015efaf in boost::object_cache::do_get () from /opt/viamedia/dependencies/lib/boost/libboost_regex-gcc-mt-1_33_1.so.1.33.1 Here is a copy of the backtrace: (gdb) bt #0 0x0015efaf in boost::object_cache::do_get () from /opt/viamedia/dependencies/lib/boost/libboost_regex-gcc-mt-1_33_1.so.1.33.1 #1 0x0015fbd9 in boost::object_cache::get () from /opt/viamedia/dependencies/lib/boost/libboost_regex-gcc-mt-1_33_1.so.1.33.1 #2 0x001767f7 in boost::basic_regex >::do_assign () from /opt/viamedia/dependencies/lib/boost/libboost_regex-gcc-mt-1_33_1.so.1.33.1 #3 0x007a0e0a in boost::basic_regex >::assign ( this=0xbfd3f030, p1=0x98bff24 "database#name\"vmcrm\"\\.(.*)", p2=0x98bff3e "", f=0) at /opt/viamedia/dependencies/include/boost/regex/v4/basic_regex.hpp:254 #4 0x007a0e4f in boost::basic_regex >::assign ( this=0xbfd3f030, p=0x98bff24 "database#name\"vmcrm\"\\.(.*)", f=0) at /opt/viamedia/dependencies/include/boost/regex/v4/basic_regex.hpp:239 #5 0x007a0e98 in basic_regex (this=0xbfd3f030, p=0x98bff24 "database#name\"vmcrm\"\\.(.*)", f=0) at /opt/viamedia/dependencies/include/boost/regex/v4/basic_regex.hpp:208 Any help would be much appreciated! thanks