Inventory Valuation - NEED HELP!!!

I just found something extremely concerning on my inventory valuation detail report.  I have line items that have zero in the quantity column but a positive amount in the inventory valuation column.  For example, I have zero yellow widgets but the valuation of those widgets is $199.90.

Even more concerning is one item that has a -15 quantity (negative) but a positive valuation of $6,797.71!!  When I drill down, I see that some of the transactions on that item have a per unit value of $486.  These items are less than $3 each!!

I called support and after 2 hours on the phone, they were baffled as well.  We looked at how we were entering the landed cost on the item receipts and they were all fine.  They set up case #542634 and said that they would "look into this" within the next 60 days.  Our fiscal year end is March 31st and my financials need to be correct at that time.  This is obviously skewing our numbers pretty dramatically.