Inventory-Avarage Cost is not correct

I have some ledger entries for one item but i see that unit cost with avarage costing method is not calculated ok.

The opening balances was for qty10 with unit cost 100 Eu, i have posted one invoices at 05/01/10 with qty 5 and unit cost 100. At 03/02/10, i have posted a purchase invoice with quanity 6 with unit cost 110.

Than at 05/2/10 i have posted a sales invices, but the unit cost is claculated for this sales invoices 100 not

105.4545

.I have run the the Adjust Cost-Item Entres batch but not resultat, Which is the problem.

Can any one to give me any suggestion.

Thanks in advance.