I'm not familiar with StopZilla therefore I cannot offer any real insight; however, anti-spyware software should not affect PostgreSQL and if it is then it would be a bug within the anti-spyware software.
I suggest contacting StopZilla, notifying them of the problem, and requesting a fix/work-around.
On a side note, simply restarting PostgreSQL should resolve the issue. Go Start->Programs->PostgreSQL 8.3->Stop Service then Start->Programs->PostgreSQL 8.3->Start Service. This is easier than doing a Windows restart.

Best regards,
Derek