diff --git a/autobuild.xml b/autobuild.xml
--- a/autobuild.xml
+++ b/autobuild.xml
@@ -2125,7 +2125,6 @@
                   <string>-G</string>
                   <string>"Visual Studio 10"</string>
                   <string>-DUNATTENDED:BOOL=ON</string>
-                  <string>-DUSE_PRECOMPILED_HEADERS=ON</string>
                   <string>-DINSTALL_PROPRIETARY=TRUE</string>
                   <string>-DUSE_KDU=FALSE</string>
                   <string>-DFMOD=FALSE</string>
@@ -2203,7 +2202,6 @@
                   <string>-G</string>
                   <string>"Visual Studio 10"</string>
                   <string>-DUNATTENDED:BOOL=ON</string>
-                  <string>-DUSE_PRECOMPILED_HEADERS=ON</string>
                   <string>-DINSTALL_PROPRIETARY=TRUE</string>
                   <string>-DUSE_KDU=FALSE</string>
                   <string>-DFMOD=FALSE</string>
@@ -2280,7 +2278,6 @@
                   <string>-G</string>
                   <string>"Visual Studio 10"</string>
                   <string>-DUNATTENDED:BOOL=ON</string>
-                  <string>-DUSE_PRECOMPILED_HEADERS=ON</string>
                   <string>-DINSTALL_PROPRIETARY=TRUE</string>
                   <string>-DUSE_KDU=FALSE</string>
                   <string>-DFMOD=FALSE</string>
diff --git a/build.sh b/build.sh
--- a/build.sh
+++ b/build.sh
@@ -58,7 +58,6 @@
     "$AUTOBUILD" configure -c $variant -- \
      -DPACKAGE:BOOL=ON \
      -DRELEASE_CRASH_REPORTING:BOOL=ON \
-     -DUSE_PRECOMPILED_HEADERS=FALSE \
      -DVIEWER_CHANNEL:STRING="\"$viewer_channel\"" \
      -DVIEWER_LOGIN_CHANNEL:STRING="\"$viewer_login_channel\"" \
      -DGRID:STRING="\"$viewer_grid\"" \
diff --git a/indra/cmake/00-Common.cmake b/indra/cmake/00-Common.cmake
--- a/indra/cmake/00-Common.cmake
+++ b/indra/cmake/00-Common.cmake
@@ -36,6 +36,13 @@
   # Don't build DLLs.
   set(BUILD_SHARED_LIBS OFF)
 
+  # for "backwards compatibility", cmake sneaks in the Zm1000 option which royally
+  # screws incredibuild. this hack disables it.
+  # for details see: http://connect.microsoft.com/VisualStudio/feedback/details/368107/clxx-fatal-error-c1027-inconsistent-values-for-ym-between-creation-and-use-of-precompiled-headers
+  # http://www.ogre3d.org/forums/viewtopic.php?f=2&t=60015
+  # http://www.cmake.org/pipermail/cmake/2009-September/032143.html
+  string(REPLACE "/Zm1000" " " CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS})
+
   set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /Od /Zi /MDd /MP -D_SCL_SECURE_NO_WARNINGS=1"
       CACHE STRING "C++ compiler debug options" FORCE)
   set(CMAKE_CXX_FLAGS_RELWITHDEBINFO 
diff --git a/indra/cmake/Variables.cmake b/indra/cmake/Variables.cmake
--- a/indra/cmake/Variables.cmake
+++ b/indra/cmake/Variables.cmake
@@ -151,7 +151,7 @@
 endif (LINUX AND SERVER AND VIEWER)
 
 
-set(USE_PRECOMPILED_HEADERS OFF CACHE BOOL "Enable use of precompiled header directives where supported.")
+set(USE_PRECOMPILED_HEADERS ON CACHE BOOL "Enable use of precompiled header directives where supported.")
 
 source_group("CMake Rules" FILES CMakeLists.txt)