Hi Michael - sorry for the delay.
I've tried the demo (
http://www.daypilot.org/demo/Calendar/) with IE7 and IE6 and it works as expected.
You are right that it has something to do with the initialization JavaScript.
Questions:
1. What version of IE do you use?
2. What version of DayPilot do you use?
3. Is there any JavaScript error during the initial loading?