Hi Sarang,

I was experiencing the same problem as well. The problem is that the default visibility for each element hidden by the calendar is updated to that element's current visibility whenever the calendar is dragged. This makes the stored default to be 'hidden' for all elements already hidden by the calendar. I'm not sure if this has been included in an updated release yet or not, but it looks to be a bug.

Problem code (Calendar.prototype.hideShowCovered funcion in Calendar.js):
cc.__msh_save_visibility = cc.style.visibility;

My fix:
if (typeof(cc.__msh_save_visibility) == 'undefined')
{
cc.__msh_save_visibility = cc.style.visibility;
}

After this fix, everything seemed to work smoothly when dragging the calendar (IE6).

Hope this helps,
Brian