A value of 0 indicates that the business object AR_InvoiceHistoryTracking_BUS is not initialized. There are quite a few places in the system where the AR_InvoiceHistoryTracking table is opened, read and written to, especially SO sales journal update, (this is not uncommon in Mas and is done largely for perfomance), but only one place where this business object is instantiated and that is from the creation of AR_InvoiceHistoryTracking_UI - not sure how this helps, but I am quite sure your problem is NOT OS or 90 vs 200 related.