diff --git a/sc/source/filter/oox/formulaparser.cxx b/sc/source/filter/oox/formulaparser.cxx
index 77ecaee..398ed3a 100644
--- a/sc/source/filter/oox/formulaparser.cxx
+++ b/sc/source/filter/oox/formulaparser.cxx
@@ -26,6 +26,7 @@
 #include <com/sun/star/sheet/NameToken.hpp>
 #include <com/sun/star/sheet/ReferenceFlags.hpp>
 #include <com/sun/star/sheet/SingleReference.hpp>
+#include <osl/thread.hxx>
 #include <oox/core/filterbase.hxx>
 #include <oox/token/properties.hxx>
 #include "addressconverter.hxx"
@@ -703,10 +704,26 @@ Any& FormulaParserImpl::appendRawToken( sal_Int32 nOpCode )
     return maTokenStorage.append( nOpCode );
 }
 
+osl::Mutex aHack;
+
 Any& FormulaParserImpl::insertRawToken( sal_Int32 nOpCode, size_t nIndexFromEnd )
 {
-    maTokenIndexes.insert( maTokenIndexes.end() - nIndexFromEnd, maTokenStorage.size() );
-    return maTokenStorage.append( nOpCode );
+    fprintf(stderr, "FormulaParserImpl::insertRawToken %p %ld %ld %d\n", this, maTokenIndexes.size(), nIndexFromEnd, osl_getThreadIdentifier(NULL));
+    fprintf(stderr, "trying to acquire %p in %d\n", this, osl_getThreadIdentifier(NULL));
+    assert(aHack.tryToAcquire());
+    try
+    {
+        maTokenIndexes.insert( maTokenIndexes.end() - nIndexFromEnd, maTokenStorage.size() );
+        Any& foo = maTokenStorage.append( nOpCode );
+        aHack.release();
+        fprintf(stderr, "released %p in %d\n", this, osl_getThreadIdentifier(NULL));
+        return foo;
+    }
+    catch(...)
+    {
+        fprintf(stderr, "WHAT THE FUCK\n");
+        throw;
+    }
 }
 
 size_t FormulaParserImpl::appendWhiteSpaceTokens( const WhiteSpaceVec* pSpaces )