Index: wview-5.19.0-jgoerzen/stations/WMRUSB/wmrusbprotocol.c
===================================================================
--- wview-5.19.0-jgoerzen.orig/stations/WMRUSB/wmrusbprotocol.c	2012-12-15 15:32:03.000000000 +0000
+++ wview-5.19.0-jgoerzen/stations/WMRUSB/wmrusbprotocol.c	2012-12-15 15:36:47.199715376 +0000
@@ -70,12 +70,9 @@
 {
     a &= 0xff;
     b &= 0xff;
-    int t = (b << 8) | a;
-    if (t & 0x8000)
-    {
-        t &= 0x7FFF;
+    int t = ((b & 0x0f) << 8) | a;
+    if (b & 0x80)
         return -(t / 10.0);
-    }
     else
         return t / 10.0;
 }
@@ -166,6 +163,9 @@
             return;
         }
 
+        if (ptr[5] & 0x20)
+            dew = ARCHIVE_VALUE_NULL;
+
         wmrWork.sensorData.humidity[sensor] = humid;
         wmrWork.sensorData.temp[sensor]     = temp;
         wmrWork.sensorData.dewpoint[sensor] = dew;