Thanks, Alan. FYI - more research on the topic, I did an ldd on the rlm_exec file: On a freeradius box I have which is working, I did: radius1:/usr/lib/freeradius # ldd rlm_exec-1.0.0.so linux-gate.so.1 => (0xffffe000) libnsl.so.1 => /lib/libnsl.so.1 (0x40018000) libresolv.so.2 => /lib/libresolv.so.2 (0x4002f000) libpthread.so.0 => /lib/tls/libpthread.so.0 (0x40042000) libcrypto.so.0.9.7 => /usr/lib/libcrypto.so.0.9.7 (0x40054000) libssl.so.0.9.7 => /usr/lib/libssl.so.0.9.7 (0x40145000) libc.so.6 => /lib/tls/libc.so.6 (0x40175000) /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x80000000) libdl.so.2 => /lib/libdl.so.2 (0x4028b000) Then on the radius box I updated and broke I did: radius2:/usr/lib/freeradius # ldd rlm_exec-1.0.0.so linux-gate.so.1 => (0xffffe000) libnsl.so.1 => /lib/libnsl.so.1 (0x55577000) libresolv.so.2 => /lib/libresolv.so.2 (0x5558e000) libpthread.so.0 => /lib/tls/libpthread.so.0 (0x555a1000) libcrypto.so.0.9.7 => /usr/lib/libcrypto.so.0.9.7 (0x555b3000) libssl.so.0.9.7 => /usr/lib/libssl.so.0.9.7 (0x556a4000) libc.so.6 => /lib/tls/libc.so.6 (0x556d4000) /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x56555000) libdl.so.2 => /lib/libdl.so.2 (0x557ea000) I hunted down and verified that every library that was pointed to by rlm_exec indeed existed on the file system. On both systems, they had everything except both had no linux-gate.so.1. But then radius1 works fine and it shows the same paths and library existence as the radius2 box which fails. Also, googling linux-gate.so.1 I saw: "What is linux-gate.so.1?": http://www.trilithium.com/johan/2005/08/ linux-gate/ and http://kerneltrap.org/node/3405 The first link explains that an ldd report of linux-gate.so.1 that doesn't point to a file/path is normal in recent kernels and goes into detail of what it is. In any case, it's not a problem. After verifying that every library that is pointed to by rlm_exec-1.0.0.so actually exists on both the machine that works fine and the one that doesn't, I understand a little more but don't see what the problem is. There's something else bizarre going on...or perhaps I still need to run ldd on each of the dependent libraries - maybe there's one in that tree of dependencies that's missing. I'll also try going to 1.0.5. Thanks, Landon