GL postings created by Value Entry posting in prior period

Hi All,

We're having a strange issue that we haven't had since 2007 when we implemented Navision.

This concerns some inventory transactions that decrease inventory, with a posting date of February. When the Value Entry adjustments are running, and trying to create the rounding transaction, they require the period of January to be open, because the transaction is trying to post on January 1, 2011, even though the posting date of the transaction is February 15, 2012.

I'm wondering what could cause this posting of the prior month's date, when the transaction has a posting date with the current month.

The transaction looks like:
1410, Rounding on 01/01/12, 0.03
5131, Rounding on 01/01/12, -0.03

I know this is a normal transaction, even though I don't know specifically what it does. But it's also not normal for our implementation for this transaction to happen on the prior month, and not the current month.

I've been able to track down that this happens when the last of a Remaining Quantity gets adjusted out of an Item Ledger Entry, and then the Value Entry adjustment gets made. But, I'm not really sure what the next step in my research would be.

Thanks in advance! I will really appreciate any help or advice or questions.