diff --git a/src/DBAccess.cpp b/src/DBAccess.cpp
index 3fd2b2da4..7a924e39b 100644
--- a/src/DBAccess.cpp
+++ b/src/DBAccess.cpp
@@ -61,8 +61,9 @@
 // 39  18  Aug 2012 Mark Liversedge    New metric LRBalance
 // 40  20  Oct 2012 Mark Liversedge    Lucene search/filter and checkbox metadata field
 // 41  27  Oct 2012 Mark Liversedge    Lucene switched to StandardAnalyzer and search all texts by default
+// 42  03  Dec 2012 Mark Liversedge    W/KG ridefilecache changes - force a rebuild.
 
-static int DBSchemaVersion = 41;
+static int DBSchemaVersion = 42;
 
 DBAccess::DBAccess(MainWindow* main, QDir home) : main(main), home(home)
 {
diff --git a/src/PowerHist.h b/src/PowerHist.h
index 7d83e50be..672b68b61 100644
--- a/src/PowerHist.h
+++ b/src/PowerHist.h
@@ -171,7 +171,7 @@ class PowerHist : public QwtPlot
 
         // discritized unit for smoothing
         static const double wattsDelta = 1.0;
-        static const double wattsKgDelta = 0.1;
+        static const double wattsKgDelta = 0.01;
         static const double nmDelta    = 0.1;
         static const double hrDelta    = 1.0;
         static const double kphDelta   = 0.1;
@@ -179,7 +179,7 @@ class PowerHist : public QwtPlot
 
         // digits for text entry validator
         static const int wattsDigits = 0;
-        static const int wattsKgDigits = 1;
+        static const int wattsKgDigits = 2;
         static const int nmDigits    = 1;
         static const int hrDigits    = 0;
         static const int kphDigits   = 1;
diff --git a/src/RideFileCache.cpp b/src/RideFileCache.cpp
index 7977d6c5d..cf8aa25e8 100644
--- a/src/RideFileCache.cpp
+++ b/src/RideFileCache.cpp
@@ -820,7 +820,11 @@ RideFileCache::computeDistribution(QVector<float> &array, RideFile::SeriesType s
     array.resize(max-min);
 
     foreach(RideFilePoint *dp, ride->dataPoints()) {
-        double value = dp->value(series);
+        double value = dp->value(baseSeries);
+        if (series == RideFile::wattsKg) {
+            value /= ride->getWeight();
+        }
+
         float lvalue = value * pow(10, decimals);
 
         // watts time in zone
@@ -1108,7 +1112,7 @@ void RideFileCache::doubleArray(QVector<double> &into, QVector<float> &from, Rid
 {
     double divisor = pow(10, decimalsFor(series)); // ? 10 : 1;
     into.resize(from.size());
-    for(int i=0; i<from.size(); i++) into[i] = from[i] / divisor;
+    for(int i=0; i<from.size(); i++) into[i] = double(from[i]) / divisor;
 
     return;
 }
diff --git a/src/RideFileCache.h b/src/RideFileCache.h
index acf048201..f45e43921 100644
--- a/src/RideFileCache.h
+++ b/src/RideFileCache.h
@@ -38,7 +38,7 @@ typedef double data_t;
 // arrays when plotting CP curves and histograms. It is precoputed
 // to save time and cached in a file .cpx
 //
-static const unsigned int RideFileCacheVersion = 6;
+static const unsigned int RideFileCacheVersion = 7;
 // revision history:
 // version  date         description
 // 1        29-Apr-11    Initial - header, mean-max & distribution data blocks
@@ -47,6 +47,7 @@ static const unsigned int RideFileCacheVersion = 6;
 // 4        02-May-11    Moved to Mark Rages mean-max function with higher precision
 // 5        18-Aug-11    Added VAM mean maximals
 // 6        27-Jun-12    Added W/kg mean maximals and distribution
+// 7        03-Dec-12    Fixed W/kg calculations!
 
 // The cache file (.cpx) has a binary format:
 // 1 x Header data - describing the version and contents of the cache