Inventory closing make corrections for transactions in closed periods

It was on previous project where I first took part as a manager. The project was completed successfully, but some questions have no answers till now. One of them is why inventory closing functionality makes corrections for transactions in closed periods. It is huge headache for all users. Fortunately it happens rarely, that is why solution of this issue was suspended. When I visited masterclass at December 2007 arranged by Microsoft in Moscow, I asked this question, but got no answer. I am going to investigate inventory closing algorithm more deeply, but if anybody has decision, be welcome.