diff -u -r -x .svn ./a/mythtv/libs/libmythtv/videoout_xv.cpp ./b/mythtv/libs/libmythtv/videoout_xv.cpp
--- ./a/mythtv/libs/libmythtv/videoout_xv.cpp	2007-05-27 13:05:40.000000000 +0200
+++ ./b/mythtv/libs/libmythtv/videoout_xv.cpp	2007-05-27 13:44:28.000000000 +0200
@@ -278,6 +278,8 @@
 
 int VideoOutputXv::GetRefreshRate(void)
 {
+    double rate;
+
     if (!XJ_started)
         return -1;
 
@@ -294,8 +296,12 @@
         return -1;
     }
 
-    double rate = (double)((double)(dot_clock * 1000.0) /
-                           (double)(mode_line.htotal * mode_line.vtotal));
+    // See if there's valid data to prevent a divide by zero.
+    if (mode_line.htotal * mode_line.vtotal > 0)
+        rate = (double)((double)(dot_clock * 1000.0) /
+                        (double)(mode_line.htotal * mode_line.vtotal));
+    else
+        rate = 60.09; // or zero...
 
     // Assume 60Hz if we can't otherwise determine it.
     if (rate == 0)
@@ -308,6 +314,8 @@
         rate = 60;
     }
 
+    VERBOSE(VB_PLAYBACK, LOC + QString("Refresh rate set to %1Hz ").arg(rate));
+
     rate = 1000000.0 / rate;
 
     return (int)rate;