I am having the same problem and it is freaking annoying as heck. I am loosing bounties and drops. I have been doing some reading and it seems it could also be a Diablo bug. For a DH when we open our inventory or get big drops to deal with. I also have the WINMr report. Here they are.
Hey my friend, We here at Diablofans are flattered that you came to us for help on this crisis! However, it may be more worth it to you if you direct this towards Blizzard themselves located at the links below.