I created a custom event content type using the instructions from http://drupal.org/node/133341 and everything worked fine. Then I wanted to enable the javascript popup calendar, so I installed Javascript Tools and enabled only the Jscalendar module. I went to test it and it popped up just fine, but when I went to preview or submit the event it would load a blank page.

To correct this, I disabled the Jscalendar module and tried submitting an event using the old drop down select list. Same problem.

Then I deleted the custom event content type all together, created a new one from scratch (using the same tutorial) and now I still get the white screen of death.