Hello, I find the following error my syslog when stopping stunnel 4.52. The program seems to be unable to shutdown cleanly (ex: pid file doesn`t get removed). stunnel: INTERNAL ERROR: Memory allocated in a different thread at network.c, line 63 This is how I configured: LDFLAGS=-Wl,-rpath,/usr/local/app/openssl/lib64 \ ./configure --prefix=/usr/local/app/stunnel \ --includedir=$PKG_HOME/openssl/include/ \ --with-ssl=$PKG_HOME/openssl/ \ --with-threads=fork \ --disable-libwrap Where PKG_HOME is a variable of my own. I had the same error with version 4.51. I do not see the error when running in foreground. I do not see the error either if I compile with threads instead of fork. In case this information is needed, this is how I configured openssl. ./config --prefix=/usr/local/app/openssl --libdir=lib64 shared zlib-dynamic no-ssl2 This is on RHEL 5.5 Regards.