diff --git a/src/mplfinance/_arg_validators.py b/src/mplfinance/_arg_validators.py
index d7398232..55c320b3 100644
--- a/src/mplfinance/_arg_validators.py
+++ b/src/mplfinance/_arg_validators.py
@@ -30,21 +30,6 @@ def _check_and_prepare_data(data, config):
     if not isinstance(data.index,pd.core.indexes.datetimes.DatetimeIndex):
         raise TypeError('Expect data.index as DatetimeIndex')
 
-    if (len(data.index) > config['warn_too_much_data'] and
-        (config['type']=='candle' or config['type']=='ohlc' or config['type']=='hollow_and_filled')
-       ):
-        warnings.warn('\n\n ================================================================= '+
-                      '\n\n   WARNING: YOU ARE PLOTTING SO MUCH DATA THAT IT MAY NOT BE'+
-                        '\n            POSSIBLE TO SEE DETAILS (Candles, Ohlc-Bars, Etc.)'+
-                        '\n   For more information see:'+
-                        '\n   - https://github.com/matplotlib/mplfinance/wiki/Plotting-Too-Much-Data'+
-                        '\n   '+
-                        '\n   TO SILENCE THIS WARNING, set `type=\'line\'` in `mpf.plot()`'+
-                        '\n   OR set kwarg `warn_too_much_data=N` where N is an integer '+
-                        '\n   LARGER than the number of data points you want to plot.'+
-                      '\n\n ================================================================ ',
-                  category=UserWarning)
-
     # We will not be fully case-insensitive (since Pandas columns as NOT case-insensitive)
     # but because so many people have requested it, for the default column names we will
     # try both Capitalized and lower case:
@@ -57,10 +42,22 @@ def _check_and_prepare_data(data, config):
     o, h, l, c, v = columns
     cols = [o, h, l, c]
 
-    if config['tz_localize']:
-        dates   = mdates.date2num(data.index.tz_localize(None).to_pydatetime())
-    else:  # Just in case someone was depending on this bug (Issue 236)
-        dates   = mdates.date2num(data.index.to_pydatetime())
+    if config['volume'] != False:
+        expect_cols = columns
+    else:
+        expect_cols = cols
+     
+    for col in expect_cols:
+        if col not in data.columns:
+            for dc in data.columns:
+                if dc.strip() != dc:
+                    warnings.warn('\n ================================================================= '+
+                                  '\n   Input DataFrame column name "'+dc+'" '+
+                                  '\n   contains leading and/or trailing whitespace.',category=UserWarning)
+            raise ValueError('Column "'+col+'" NOT FOUND in Input DataFrame!'+
+                             '\n            CHECK that your column names are correct AND/OR'+
+                             '\n            CHECK for leading or trailing blanks in your column names.')
+
     opens   = data[o].values
     highs   = data[h].values
     lows    = data[l].values
@@ -75,6 +72,26 @@ def _check_and_prepare_data(data, config):
         if not all( isinstance(v,(float,int)) for v in data[col] ):
             raise ValueError('Data for column "'+str(col)+'" must be ALL float or int.')
 
+    if config['tz_localize']:
+        dates   = mdates.date2num(data.index.tz_localize(None).to_pydatetime())
+    else:  # Just in case someone was depending on this bug (Issue 236)
+        dates   = mdates.date2num(data.index.to_pydatetime())
+
+    if (len(data.index) > config['warn_too_much_data'] and
+        (config['type']=='candle' or config['type']=='ohlc' or config['type']=='hollow_and_filled')
+       ):
+        warnings.warn('\n\n ================================================================= '+
+                      '\n\n   WARNING: YOU ARE PLOTTING SO MUCH DATA THAT IT MAY NOT BE'+
+                        '\n            POSSIBLE TO SEE DETAILS (Candles, Ohlc-Bars, Etc.)'+
+                        '\n   For more information see:'+
+                        '\n   - https://github.com/matplotlib/mplfinance/wiki/Plotting-Too-Much-Data'+
+                        '\n   '+
+                        '\n   TO SILENCE THIS WARNING, set `type=\'line\'` in `mpf.plot()`'+
+                        '\n   OR set kwarg `warn_too_much_data=N` where N is an integer '+
+                        '\n   LARGER than the number of data points you want to plot.'+
+                      '\n\n ================================================================ ',
+                  category=UserWarning)
+
     return dates, opens, highs, lows, closes, volumes
 
 def _get_valid_plot_types(plottype=None):
diff --git a/src/mplfinance/_version.py b/src/mplfinance/_version.py
index e16ebafe..52221d42 100644
--- a/src/mplfinance/_version.py
+++ b/src/mplfinance/_version.py
@@ -1,4 +1,4 @@
-version_info = (0, 12, 9, 'beta', 4)
+version_info = (0, 12, 9, 'beta', 5)
 
 _specifier_ = {'alpha': 'a','beta': 'b','candidate': 'rc','final': ''}
 
diff --git a/src/mplfinance/plotting.py b/src/mplfinance/plotting.py
index 4826b42c..4e849f92 100644
--- a/src/mplfinance/plotting.py
+++ b/src/mplfinance/plotting.py
@@ -1235,7 +1235,7 @@ def _auto_secondary_y( panels, panid, ylo, yhi ):
 
 def _valid_addplot_kwargs():
 
-    valid_linestyles = ('-','solid','--','dashed','-.','dashdot','.','dotted',None,' ','')
+    valid_linestyles = ('-','solid','--','dashed','-.','dashdot',':','dotted',None,' ','')
     valid_types = ('line','scatter','bar', 'ohlc', 'candle','step')
     valid_stepwheres = ('pre','post','mid')
     valid_edgecolors = ('face', 'none', None)