All day Event Check Box in the Z Date type is not working

Hi dude,

I tried add a new Z date type in the stand Date Profile of the Activity transaction type in SAP CRM 7.0 EHP3.

All day Event check box present in the Date Assignment Block clear automatically when we press the save button for our Z Date Type, but in case of stand date type 'orderactual' its not clearing.

Any one explain me about where we need to configure for this to activate All day event Activity in Date Type/Access Type/date Profile.

help full answer will be rewarded. Thanks in advance.

Reg,

Hariharan.