I looked at the principal's website and from the postings (that have not been answered yet), it looks like other parents have been given the boot (like I was this morning) as well:
"I would like clarification on the school's policy for times permitted to walk through your school grounds. I was just told this morning that I could not walk through the school common area after having dropped off my son at your school. Are parents also not allowed to walk through your school grounds on their through your school grounds on their way to drop children off? You may have mentioned this policy in your annual introduction talk at the beginning of the school year but I cannot remember the details."