diff --git a/src/nsLanguageDetector.cpp b/src/nsLanguageDetector.cpp
index 0b5baa1..8097028 100644
--- a/src/nsLanguageDetector.cpp
+++ b/src/nsLanguageDetector.cpp
@@ -212,7 +212,7 @@ float nsLanguageDetector::GetConfidence(void)
     //float neutralSeqs  = mSeqCounters[LANG_NEUTRAL_CAT];
     float negativeSeqs = mSeqCounters[LANG_NEGATIVE_CAT];
 
-    r = (positiveSeqs + probableSeqs / 4 - negativeSeqs * 2) / mTotalSeqs;
+    r = (positiveSeqs + probableSeqs / 4 - negativeSeqs * 4) / mTotalSeqs / mModel->mTypicalPositiveRatio;
     /* The more characters outside the expected characters
      * (proportionnaly to the size of the text), the less confident we
      * become in the current language.
diff --git a/src/nsSBCharSetProber.cpp b/src/nsSBCharSetProber.cpp
index 2dfe830..a51cea1 100644
--- a/src/nsSBCharSetProber.cpp
+++ b/src/nsSBCharSetProber.cpp
@@ -48,11 +48,8 @@ nsProbingState nsSingleByteCharSetProber::HandleData(const char* aBuf, PRUint32
   {
     order = mModel->charToOrderMap[(unsigned char)aBuf[i]];
 
-    if (order < SYMBOL_CAT_ORDER)
-    {
-      mTotalChar++;
-    }
-    else if (order == ILL)
+    mTotalChar++;
+    if (order == ILL)
     {
       /* When encountering an illegal codepoint, no need
        * to continue analyzing data. */
@@ -63,7 +60,7 @@ nsProbingState nsSingleByteCharSetProber::HandleData(const char* aBuf, PRUint32
     {
       mCtrlChar++;
     }
-    if (order < mModel->freqCharCount)
+    else if (order < mModel->freqCharCount)
     {
       mFreqChar++;
 
@@ -75,6 +72,21 @@ nsProbingState nsSingleByteCharSetProber::HandleData(const char* aBuf, PRUint32
         else // reverse the order of the letters in the lookup
           ++(mSeqCounters[mModel->precedenceMatrix[order*mModel->freqCharCount+mLastOrder]]);
       }
+      else if (mLastOrder < SYMBOL_CAT_ORDER)
+      {
+        mSeqCounters[NEGATIVE_CAT]++;
+        mTotalSeqs++;
+      }
+    }
+    else if (order < SYMBOL_CAT_ORDER)
+    {
+      mOutChar++;
+
+      if (mLastOrder < SYMBOL_CAT_ORDER)
+      {
+        mTotalSeqs++;
+        mSeqCounters[NEGATIVE_CAT]++;
+      }
     }
     mLastOrder = order;
   }
@@ -92,7 +104,7 @@ nsProbingState nsSingleByteCharSetProber::HandleData(const char* aBuf, PRUint32
   return mState;
 }
 
-void  nsSingleByteCharSetProber::Reset(void)
+void nsSingleByteCharSetProber::Reset(void)
 {
   mState = eDetecting;
   mLastOrder = 255;
@@ -101,7 +113,8 @@ void  nsSingleByteCharSetProber::Reset(void)
   mTotalSeqs = 0;
   mTotalChar = 0;
   mCtrlChar  = 0;
-  mFreqChar = 0;
+  mFreqChar  = 0;
+  mOutChar   = 0;
 }
 
 //#define NEGATIVE_APPROACH 1
@@ -117,23 +130,14 @@ float nsSingleByteCharSetProber::GetConfidence(int candidate)
   float r;
 
   if (mTotalSeqs > 0) {
-    r = ((float)1.0) * mSeqCounters[POSITIVE_CAT] / mTotalSeqs / mModel->mTypicalPositiveRatio;
-    /* Multiply by a ratio of positive sequences per characters.
-     * This would help in particular to distinguish close winners.
-     * Indeed if you add a letter, you'd expect the positive sequence count
-     * to increase as well. If it doesn't, it may mean that this new codepoint
-     * may not have been a letter, but instead a symbol (or some other
-     * character). This could make the difference between very closely related
-     * charsets used for the same language.
-     */
-    r = r * (mSeqCounters[POSITIVE_CAT] + (float) mSeqCounters[PROBABLE_CAT] / 4) / mTotalChar;
-    /* The more control characters (proportionnaly to the size of the text), the
-     * less confident we become in the current charset.
-     */
-    r = r * ((float) mTotalChar - mCtrlChar) / mTotalChar;
-    r = r*mFreqChar/mTotalChar;
-    if (r >= (float)1.00)
-      r = (float)0.99;
+    float positiveSeqs = mSeqCounters[POSITIVE_CAT];
+    float probableSeqs = mSeqCounters[PROBABLE_CAT];
+    float negativeSeqs = mSeqCounters[NEGATIVE_CAT];
+
+    r = (positiveSeqs + probableSeqs / 4 - negativeSeqs * 4) / mTotalSeqs / mModel->mTypicalPositiveRatio;
+    r = r * (mTotalChar - mOutChar - mCtrlChar) / mTotalChar;
+    r = r * mFreqChar / mTotalChar;
+
     return r;
   }
   return (float)0.01;
diff --git a/src/nsSBCharSetProber.h b/src/nsSBCharSetProber.h
index f52bf2c..f6173a8 100644
--- a/src/nsSBCharSetProber.h
+++ b/src/nsSBCharSetProber.h
@@ -124,6 +124,7 @@ protected:
   PRUint32 mCtrlChar;
   //characters that fall in our sampling range
   PRUint32 mFreqChar;
+  PRUint32 mOutChar;
   
   // Optional auxiliary prober for name decision. created and destroyed by the GroupProber
   nsCharSetProber* mNameProber;