Abnormal posting date entries happens when the Posting Date of the receipt/shipments of inventory is after the Posting Date of the invoice. Why does this happen? You'll need to ask your CFO or Controller. Typically, I found this more in return orders where the receipt of the product is a certain date, and the accounting department decides to post the credit memo in prior dates.
Either by mistake or intentional, if this happens, your Inventory Valuation will not tie to your G/L.
Here's a step by step on how to replicate this problem, and how to solve this problem:1. Create a sales order with posting date of 11/01/082. Post the Shipment with a posting date of 11/01/083. Change the posting date to 09/01/084. Post the invoice5. Run your inventory valuation report as of 9/30/086. Notice that the item is not taken out? But if you look at your G/L, the inventory value is taken out.
This will work for purchase side as well. It doesn't matter how to do it either using warehouse shipment/receive, the underlying process will net you the same problem.
Usually, problems like this won't come up until the user is trying to do month end and gets really frustrated on why their inventory doesn't tie to G/L. Unfortunately, there's no easy way to reverse this transaction after it's posted, the only way is to run a report at the end of the period to see what transactions have this "Abnormal Posting Dates".
Here's a report that will give you all the transactions that have abnormal posting dates. If you take this amount, add/subtract it to your inventory valuation report, it will be equal to the G/L inventory.
To run this report, just put the period you want to close on the Posting Date field. For example, if you're trying to close November 2008, then your Posting Date filter should be 11/1/08..11/30/08.
Here' the link for the report: