How to correct item costs?

Hi, For one of our customers, we are implementing the production and capacity planning related granules. We had some wrong cost values in the machine center cards. After the production transactions with these values, we ran the adjust cost-item entries batch job. As a result, the cost amount(actual) field of the item ledger entries are incorrect and the average cost is also incorrect for the items we produce. We want to fix this. Can Inventory revaluation be a solution? It works for the raw materials. What about WIP items and the products? I tried some examples. The revaluation journal calculates the quantity according to the completely invoiced field in the item ledger entries. I enter the unit cost (revalued) as the one it should be. After running adjust cost-item entries batch job, the result is again incorrect. If I revalue the entries manually, the result is again different. [:(] Is it impossible? Does anyone have a suggestion? Thanks in advance

Well if you want to let us into the big secret of what costing method you are using, we can start to help.

Average costing method is used. Now please help. [:)]