diff --git a/mozilla/htmlparser/src/nsExpatTokenizer.cpp b/mozilla/htmlparser/src/nsExpatTokenizer.cpp
index e9923130a65..5fad29e7e20 100644
--- a/mozilla/htmlparser/src/nsExpatTokenizer.cpp
+++ b/mozilla/htmlparser/src/nsExpatTokenizer.cpp
@@ -133,6 +133,7 @@ void nsExpatTokenizer::SetupExpatCallbacks(void) {
 nsExpatTokenizer::nsExpatTokenizer() : nsHTMLTokenizer() {
   NS_INIT_REFCNT();
   mBytesParsed = 0;
+  mSeenError = PR_FALSE;
   mExpatParser = XML_ParserCreate(NULL);
   gTokenRecycler=(CTokenRecycler*)GetTokenRecycler();
   if (mExpatParser) {
@@ -148,8 +149,10 @@ nsExpatTokenizer::nsExpatTokenizer() : nsHTMLTokenizer() {
  *  @return  
  */
 nsExpatTokenizer::~nsExpatTokenizer(){
-  if (mExpatParser)
-    XML_ParserFree(mExpatParser);  
+  if (mExpatParser) {
+    XML_ParserFree(mExpatParser);
+    mExpatParser = nsnull;
+  }
 }
 
 
@@ -232,10 +235,13 @@ nsresult nsExpatTokenizer::ParseXMLBuffer(const char *aBuffer, PRUint32 aLength)
   nsresult result=NS_OK;
   if (mExpatParser) {
     PR_ASSERT(aLength == strlen(aBuffer));
-    if (!XML_Parse(mExpatParser, aBuffer, aLength, PR_FALSE)) {
-      PushXMLErrorToken(aBuffer, aLength);      
-    }    
-	  mBytesParsed += aLength;    
+    if (!mSeenError) {
+      if (!XML_Parse(mExpatParser, aBuffer, aLength, PR_FALSE)) {
+        PushXMLErrorToken(aBuffer, aLength);
+        mSeenError = PR_TRUE;
+      }
+	    mBytesParsed += aLength;
+    }
   }
   else {
     result = NS_ERROR_FAILURE;
diff --git a/mozilla/htmlparser/src/nsExpatTokenizer.h b/mozilla/htmlparser/src/nsExpatTokenizer.h
index 386e7899a21..9c79b0e3d56 100644
--- a/mozilla/htmlparser/src/nsExpatTokenizer.h
+++ b/mozilla/htmlparser/src/nsExpatTokenizer.h
@@ -107,6 +107,7 @@ protected:
   
     XML_Parser mExpatParser;
 	PRUint32 mBytesParsed;
+  PRBool mSeenError;
 };
 
 extern NS_HTMLPARS nsresult NS_Expat_Tokenizer(nsIDTD** aInstancePtrResult);
diff --git a/mozilla/htmlparser/src/nsWellFormedDTD.cpp b/mozilla/htmlparser/src/nsWellFormedDTD.cpp
index df174fb96c3..1833f7eb426 100644
--- a/mozilla/htmlparser/src/nsWellFormedDTD.cpp
+++ b/mozilla/htmlparser/src/nsWellFormedDTD.cpp
@@ -330,18 +330,18 @@ nsITokenRecycler* CWellFormedDTD::GetTokenRecycler(void){
  */
 nsITokenizer* CWellFormedDTD::GetTokenizer(void) {
   if(!mTokenizer) {
-    PRBool  theExpatState=PR_FALSE;
+    PRBool  theExpatState=PR_TRUE;
 #ifndef XP_MAC
-    char* theEnvString = PR_GetEnv("EXPAT");
+    char* theEnvString = PR_GetEnv("NOEXPAT");
     if(theEnvString){
       if(('1'==theEnvString[0]) || ('Y'==theEnvString[0]) || ('y'==theEnvString[0])) {
-        theExpatState=PR_TRUE;  //this indicates that the EXPAT flag was found in the environment.
+        theExpatState=PR_FALSE;  //this indicates that the EXPAT flag was found in the environment.
       }
     }
 #else
 	// Check for the existence of a file called EXPAT in the current directory
 	nsSpecialSystemDirectory expatFile(nsSpecialSystemDirectory::OS_CurrentProcessDirectory);
-	expatFile += "EXPAT";
+	expatFile += "NOEXPAT";
 	theExpatState = expatFile.Exists();
 #endif
     if(theExpatState) {
diff --git a/mozilla/parser/htmlparser/src/nsExpatTokenizer.cpp b/mozilla/parser/htmlparser/src/nsExpatTokenizer.cpp
index e9923130a65..5fad29e7e20 100644
--- a/mozilla/parser/htmlparser/src/nsExpatTokenizer.cpp
+++ b/mozilla/parser/htmlparser/src/nsExpatTokenizer.cpp
@@ -133,6 +133,7 @@ void nsExpatTokenizer::SetupExpatCallbacks(void) {
 nsExpatTokenizer::nsExpatTokenizer() : nsHTMLTokenizer() {
   NS_INIT_REFCNT();
   mBytesParsed = 0;
+  mSeenError = PR_FALSE;
   mExpatParser = XML_ParserCreate(NULL);
   gTokenRecycler=(CTokenRecycler*)GetTokenRecycler();
   if (mExpatParser) {
@@ -148,8 +149,10 @@ nsExpatTokenizer::nsExpatTokenizer() : nsHTMLTokenizer() {
  *  @return  
  */
 nsExpatTokenizer::~nsExpatTokenizer(){
-  if (mExpatParser)
-    XML_ParserFree(mExpatParser);  
+  if (mExpatParser) {
+    XML_ParserFree(mExpatParser);
+    mExpatParser = nsnull;
+  }
 }
 
 
@@ -232,10 +235,13 @@ nsresult nsExpatTokenizer::ParseXMLBuffer(const char *aBuffer, PRUint32 aLength)
   nsresult result=NS_OK;
   if (mExpatParser) {
     PR_ASSERT(aLength == strlen(aBuffer));
-    if (!XML_Parse(mExpatParser, aBuffer, aLength, PR_FALSE)) {
-      PushXMLErrorToken(aBuffer, aLength);      
-    }    
-	  mBytesParsed += aLength;    
+    if (!mSeenError) {
+      if (!XML_Parse(mExpatParser, aBuffer, aLength, PR_FALSE)) {
+        PushXMLErrorToken(aBuffer, aLength);
+        mSeenError = PR_TRUE;
+      }
+	    mBytesParsed += aLength;
+    }
   }
   else {
     result = NS_ERROR_FAILURE;
diff --git a/mozilla/parser/htmlparser/src/nsExpatTokenizer.h b/mozilla/parser/htmlparser/src/nsExpatTokenizer.h
index 386e7899a21..9c79b0e3d56 100644
--- a/mozilla/parser/htmlparser/src/nsExpatTokenizer.h
+++ b/mozilla/parser/htmlparser/src/nsExpatTokenizer.h
@@ -107,6 +107,7 @@ protected:
   
     XML_Parser mExpatParser;
 	PRUint32 mBytesParsed;
+  PRBool mSeenError;
 };
 
 extern NS_HTMLPARS nsresult NS_Expat_Tokenizer(nsIDTD** aInstancePtrResult);
diff --git a/mozilla/parser/htmlparser/src/nsWellFormedDTD.cpp b/mozilla/parser/htmlparser/src/nsWellFormedDTD.cpp
index df174fb96c3..1833f7eb426 100644
--- a/mozilla/parser/htmlparser/src/nsWellFormedDTD.cpp
+++ b/mozilla/parser/htmlparser/src/nsWellFormedDTD.cpp
@@ -330,18 +330,18 @@ nsITokenRecycler* CWellFormedDTD::GetTokenRecycler(void){
  */
 nsITokenizer* CWellFormedDTD::GetTokenizer(void) {
   if(!mTokenizer) {
-    PRBool  theExpatState=PR_FALSE;
+    PRBool  theExpatState=PR_TRUE;
 #ifndef XP_MAC
-    char* theEnvString = PR_GetEnv("EXPAT");
+    char* theEnvString = PR_GetEnv("NOEXPAT");
     if(theEnvString){
       if(('1'==theEnvString[0]) || ('Y'==theEnvString[0]) || ('y'==theEnvString[0])) {
-        theExpatState=PR_TRUE;  //this indicates that the EXPAT flag was found in the environment.
+        theExpatState=PR_FALSE;  //this indicates that the EXPAT flag was found in the environment.
       }
     }
 #else
 	// Check for the existence of a file called EXPAT in the current directory
 	nsSpecialSystemDirectory expatFile(nsSpecialSystemDirectory::OS_CurrentProcessDirectory);
-	expatFile += "EXPAT";
+	expatFile += "NOEXPAT";
 	theExpatState = expatFile.Exists();
 #endif
     if(theExpatState) {