pip installs packages, but doesn't mark them as executable, so python doesn't find them

pip installs packages, but doesn't mark them as executable, so python
doesn't find them

I've been trying to use sudo to install python packages on a system that I
am on the sudoers list, but don't have general root access (i.e. don't
have the password for su). I can install packages, for example
sudo pip install django
however when I try and use them python simply claims not to have the
package installed. Investigating the contents of /usr/lib/python it
appears that other packages directories and .eggs have executable
permissions for ugo, however the packages I install using sudo pip do not
have this permission. Manually giving these files executable permissions
fixes the problem, but that is laborious, particularly when pip installed
several dependencies that I need to chase up.
Is this a known issue? What can I do about it? For the record this is a
RHEL6.4 machine and I'm using pip 1.4.1.