diff --git a/pytools/__init__.py b/pytools/__init__.py
index 819162ff1586ef2dbbb2f0dadbd929e5756da846..5f5a8efd0ba79d27e436b64ab88d809de4c92aef 100644
--- a/pytools/__init__.py
+++ b/pytools/__init__.py
@@ -1,5 +1,4 @@
 from __future__ import division
-import math
 import sys
 import operator
 import types
diff --git a/pytools/decorator.py b/pytools/decorator.py
index eaf0b7b6392e4c4bda2e6597671ff10682d26d36..0c668363c2d7fa1d1442edb13199c6ebecbff5f4 100644
--- a/pytools/decorator.py
+++ b/pytools/decorator.py
@@ -9,7 +9,7 @@
 
 __all__ = ["decorator", "update_wrapper", "getinfo"]
 
-import inspect, sys
+import inspect
     
 def getinfo(func):
     """
diff --git a/pytools/diskdict.py b/pytools/diskdict.py
index 51586a2c825845414081bb271e564e1213f8d130..81b7d53fa2e2d149057456e982e86458a582214f 100644
--- a/pytools/diskdict.py
+++ b/pytools/diskdict.py
@@ -84,8 +84,8 @@ class DiskDict(object):
             del self.cache[key]
 
         from cPickle import loads
-        for item_id, arg_pickle, version_pickle in self.db_conn.execute(
-                "select key_pickle, version_pickle, result_pickle from data"
+        for item_id, key_pickle, version_pickle in self.db_conn.execute(
+                "select id, key_pickle, version_pickle from data"
                 " where key_hash = ? and version_hash = ?",
                 (hash(key), self.version_hash)):
             if loads(key_pickle) == key and loads(version_pickle) == self.version:
diff --git a/pytools/grid.py b/pytools/grid.py
index e09ace5a26906a02f08758522ea5ac7ef59dd49b..a9ec2204eaf915b30426ddcb7e99c92c193f4996 100644
--- a/pytools/grid.py
+++ b/pytools/grid.py
@@ -1,7 +1,6 @@
 import pytools
-
+import math
 import pylinear.array as num
-import pylinear.linear_algebra as la
 
 
 
@@ -70,7 +69,7 @@ class Grid(object):
             neighbors = new_neighbors
         weights = []
         for neighbor in neighbors:
-            weight = product([1-abs(a-b) for a,b in zip(float_coords, neighbor)])
+            weight = pytools.product([1-abs(a-b) for a,b in zip(float_coords, neighbor)])
             if abs(weight) >= 1e-5:
                 weights.append((weight, tuple(neighbor)))
         return weights
diff --git a/pytools/lex.py b/pytools/lex.py
index edc2cbad07eca57188058a53fa5568d516baab7c..22d3ac2989b73c055a73d3fccb0cf3e0c716fbeb 100644
--- a/pytools/lex.py
+++ b/pytools/lex.py
@@ -2,7 +2,7 @@ import re
 
 class RuleError:
     def __init__(self, rule):
-        self.Rule = s
+        self.Rule = rule
 
     def __str__(self):
         return repr(self.Rule)
diff --git a/pytools/log.py b/pytools/log.py
index d5c1e36f8564b55f5426490f6b19fdaf20d61ed3..cf5b1d6629b8e45eef5b23f5ac66a4d090d4001a 100644
--- a/pytools/log.py
+++ b/pytools/log.py
@@ -580,7 +580,7 @@ class LogManager(object):
                 dub = self.get_expr_dataset(expr)
             else:
                 expr_descr, expr_unit, expr_str = expr
-                dub = get_expr_dataset(
+                dub = self.get_expr_dataset(
                         expr_str,
                         description=expr_descr,
                         unit=expr_unit)
@@ -630,6 +630,7 @@ class LogManager(object):
 
         gp.xlabel("%s [%s]" % (descr_x, unit_x))
         gp.ylabel("%s [%s]" % (descr_y, unit_y))
+        from gnuplot_py import Data
         gp.plot(Data(data_x, data_y, **kwargs))
 
     def write_datafile(self, filename, expr_x, expr_y):
@@ -637,8 +638,7 @@ class LogManager(object):
                 expr_x, expr_y)
 
         outf = open(filename, "w")
-        outf.write("# %s [%s] vs. %s [%s]" % 
-                (descr_x, unit_x, descr_y, unit_y))
+        outf.write("# %s vs. %s" % (label_x, label_y))
         for dx, dy in zip(data_x, data_y):
             outf.write("%s\t%s\n" % (repr(dx), repr(dy)))
         outf.close()