diff --git a/rowers/dataprep.py b/rowers/dataprep.py
index ae83c7c2..032d51b9 100644
--- a/rowers/dataprep.py
+++ b/rowers/dataprep.py
@@ -2059,7 +2059,11 @@ def dataprep(rowdatadf, id=0, bands=True, barchart=True, otwpower=True,
     if barchart:
         # time increments for bar chart
         time_increments = rowdatadf.ix[:, ' ElapsedTime (sec)'].diff()
-        time_increments.ix[0] = time_increments.ix[1]
+        try:
+            time_increments.ix[0] = time_increments.ix[1]
+        except KeyError:
+            time_increments.ix[0] = 1.
+            
         time_increments = 0.5 * time_increments + 0.5 * np.abs(time_increments)
         x_right = (t2 + time_increments.apply(lambda x: timedeltaconv(x)))