--- a/dataset.py	Wed May 28 14:16:32 2008 -0400
+++ b/dataset.py	Thu May 29 10:30:59 2008 -0400
@@ -1054,6 +1054,8 @@
                 assert offset>=0 and offset<len(dataset.data)
                 assert offset+minibatch_size<=len(dataset.data)
                 self.current=offset
+                self.columns = [self.dataset.fields_columns[f] 
+                                for f in self.minibatch._names]
             def __iter__(self):
                 return self
             def next(self):
@@ -1062,7 +1064,8 @@
                 if self.current>=self.dataset.data.shape[0]:
                     raise StopIteration
                 sub_data =  self.dataset.data[self.current]
-                self.minibatch._values = [sub_data[self.dataset.fields_columns[f]] for f in self.minibatch._names]
+                self.minibatch._values = [sub_data[c] for c in self.columns]
+
                 self.current+=self.minibatch_size
                 return self.minibatch