diff --git a/IPython/testing/iptest.py b/IPython/testing/iptest.py
index df4b41e..8900099 100644
--- a/IPython/testing/iptest.py
+++ b/IPython/testing/iptest.py
@@ -38,8 +38,6 @@ import warnings
 p = os.path
 ippath = p.abspath(p.join(p.dirname(__file__),'..','..'))
 sys.path.insert(0, ippath)
-#print 'ipp:',  ippath  # dbg
-#import IPython; print 'IP file:', IPython.__file__  # dbg
 
 # Note: monkeypatch!
 # We need to monkeypatch a small problem in nose itself first, before importing
@@ -240,6 +238,7 @@ class IPTester(object):
             return os.system(' '.join(self.call_args))
     else:
         def _run_cmd(self):
+            #print >> sys.stderr, '*** CMD:', ' '.join(self.call_args) # dbg
             subp = subprocess.Popen(self.call_args)
             self.pids.append(subp.pid)
             # If this fails, the pid will be left in self.pids and cleaned up
@@ -295,7 +294,7 @@ def make_runners():
         trial_pkg_names.append('kernel')
 
     # For debugging this code, only load quick stuff
-    #nose_pkg_names = ['config', 'utils']  # dbg
+    #nose_pkg_names = ['core']  # dbg
     #trial_pkg_names = []  # dbg 
 
     # Make fully qualified package names prepending 'IPython.' to our name lists
@@ -320,7 +319,20 @@ def run_iptest():
     warnings.filterwarnings('ignore', 
         'This will be removed soon.  Use IPython.testing.util instead')
 
-    argv = sys.argv + [ '--detailed-errors',
+    argv = sys.argv + [ '--detailed-errors',  # extra info in tracebacks
+                        
+                        # I don't fully understand why we need this one, but
+                        # depending on what directory the test suite is run
+                        # from, if we don't give it, 0 tests get run.
+                        # Specifically, if the test suite is run from the
+                        # source dir with an argument (like 'iptest.py
+                        # IPython.core', 0 tests are run, even if the same call
+                        # done in this directory works fine).  It appears that
+                        # if  the requested package is in the current dir,
+                        # nose bails early by default.  Since it's otherwise
+                        # harmless, leave it in by default. 
+                        '--traverse-namespace',
+                        
                         # Loading ipdoctest causes problems with Twisted, but
                         # our test suite runner now separates things and runs
                         # all Twisted tests with trial.
diff --git a/IPython/utils/platutils_posix.py b/IPython/utils/platutils_posix.py
index 9a6a62d..efcc327 100644
--- a/IPython/utils/platutils_posix.py
+++ b/IPython/utils/platutils_posix.py
@@ -49,7 +49,7 @@ else:
 
 def find_cmd(cmd):
     """Find the full path to a command using which."""
-    return getoutputerror('which %s' % cmd)[0]
+    return getoutputerror('/usr/bin/env which %s' % cmd)[0]
 
 
 def get_long_path_name(path):
diff --git a/iptest.py b/iptest.py
index 7c22381..236cb16 100755
--- a/iptest.py
+++ b/iptest.py
@@ -2,13 +2,17 @@
 """Test script for IPython.
 
 The actual ipython test script to be installed with 'python setup.py install'
-is in './scripts' directory. This file is here (ipython source root directory)
-to facilitate non-root 'zero-installation testing' (just copy the source tree
-somewhere and run ipython.py) and development.
+is in './scripts' directory, and will test IPython from an importable
+location.
+
+This file is here (ipython source root directory) to facilitate non-root
+'zero-installation testing and development' (just copy the source tree
+somewhere and run iptest.py).
 
 You can run this script directly, type -h to see all options."""
 
-# Ensure that the imported IPython is the local one, not a system-wide one
+# Ensure that the imported IPython packages come from *THIS* IPython, not some
+# other one that may exist system-wide
 import os, sys
 this_dir = os.path.dirname(os.path.abspath(__file__))
 sys.path.insert(0, this_dir)