Using a RHEL5.7 OS, I can get glade_4.1.86_linux64_rh5 to run perfectly with python_2.4.3, or python_2.6.6, or python_2.7.1. I don't make use of PYTHONHOME because my python installation is a funky wrapper-based installation. However, since 'python' is found via $PATH, glade seems to be happy. I do however set PYTHONPATH, and I confirm that I can get the API to work nicely.
After downloading the latest 4.2.7 build of glade for RHEL5, the interface refuses to load. Here is the error message I get:
Could not find platform independent libraries <prefix>
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
ImportError: No module named site