I am unable to activate the plugin. When I try, the admin screen just blanks out. From that point on, you can NOT get into WP administration. The only way I have found to get back operational is to delete the plugin from server (Renaming my-calendar.php also works.). I have downloaded the plugin twice, deleted and re-installed at 3 times. I have also checked the .htaccess per another user's same problem. Mine seems to be okay.