Project LinkActivity creation by code.

Hi,

I have written a custom code to create set of Plan and Summary Activities in Project Plan.

Activities are creating and the TimeStamp  mentioned in code for start and finish of activities are also set.

But when I create a activity manually in the Project Plan, The Summary activity time(Created via code) is reset to Project activity timestamp and all

Plan activitiesare getting changed accordingly.

SO can you suggest be where problem could be.

I found OOTB will also create HistoryXML and History Record Objects but I am not able to create them with code.

So if you have any idea about those objects then please share.

Thank You.