Composite type of information register dimension

I have Prices information register. The register is very simple, having
period: days
dimension: SKU of composite type: CatalogRef.SKUs and String
resource: Price of Number type
Data of this register is used in CustomerOrder document. Records of this register are written during the ProductReceipt document posting. Also there is prices import from spreadsheet document. If a product is not found the price is written for product code. This happens when there is stock which was before we started input of product receipt documents.
The problem is that when CustomerOrder is created prices are found not for all products. I guess that the problem is that the composite type of dimension is used for prices. Could some one give an advice on how to solve this problem?

It is better not to use a composite type in the dimensions of the register. Make an inventory of stock items and create a catalog item for each SKU.

I guess you are right, Alexey...