--- Modules/FindBoost.cmake	2012-01-10 15:29:39.556025724 -0500
+++ Modules/FindBoost.cmake	2012-01-10 15:46:54.319929166 -0500
@@ -449,9 +449,24 @@
     "${Boost_FIND_VERSION_MAJOR}.${Boost_FIND_VERSION_MINOR}.${Boost_FIND_VERSION_PATCH}"
     "${Boost_FIND_VERSION_MAJOR}.${Boost_FIND_VERSION_MINOR}")
 else(Boost_FIND_VERSION_EXACT)
+
+  # Determine the system default library.
+  execute_process(
+    COMMAND "gawk" "$2 == \"BOOST_LIB_VERSION\" {print $3}" "/usr/include/boost/version.hpp"
+    COMMAND "sed" "-e" "s/_/./g;s/\"//g"
+    OUTPUT_VARIABLE _boost_SELECTED)
+
+  # Determine the version without the ".0" or ".1", in case that finds it
+  # better.
+  string(REGEX REPLACE "([0-9]+)\\.([0-9]+)\\.([0-9]+)" "\\1.\\2"
+    _boost_SELECTED_NO_PATCH ${_boost_SELECTED})
+
   # The user has not requested an exact version.  Among known
   # versions, find those that are acceptable to the user request.
-  set(_Boost_KNOWN_VERSIONS ${Boost_ADDITIONAL_VERSIONS}
+  set(_Boost_KNOWN_VERSIONS
+    ${_boost_SELECTED}
+    ${_boost_SELECTED_NO_PATCH}
+    ${Boost_ADDITIONAL_VERSIONS}
     "1.46.1"
     "1.46.0" "1.46" "1.45.0" "1.45" "1.44.0" "1.44" "1.43.0" "1.43" "1.42.0" "1.42"
     "1.41.0" "1.41" "1.40.0" "1.40" "1.39.0" "1.39" "1.38.0" "1.38" "1.37.0" "1.37"