schudling agreement with time dependent excise base value taking wrongly.

Sub: in migo excise base amount is not changing as per the scheduling agreement type LP ( time dependent ).

I have created the scheduling agreement type LP with time dependent.

I have maintained the price value in two validated period i.e

01/07/08 to 31/07/08 price is 100 rs.

01/08/08 to 31/08/08 price is 200 rs.

I have maintained the delivery schedule on

15/07/08 of quantity 1 nos.

When I am doing the goods receipts for the scheduling agreement on

Document date I am giving 15/07/08.

Posting date I am giving 15/07/08.

I am giving the posting date in the excise also 15/07/08.

After item ok.

When I will the excise base value it is taking 200 and also excise duty is also calculating on 200.

When I will post the document

The stock account and GR/IR account is taking 100 only

And excise duty is posting for rs: 200 only

Why the excise base value is not changing as per the validity period.

What setting I have to do the change the excise base value as per the validity date maintained in the time dependent .

regards

jrp