Hey, I'm glad to see this thread come back. The problem was never resolved for me. I use Jorte, not Business Calendar. I also tried Pure Calendar, and got the same result. I think it's the Photon, not the apps. I traded a couple of emails with Jorte's support and they basically stopped responding once I had fully explained the issue.
Somewhere I thought I saw that the OTA update that everybody is getting today had a fix for something related to Exchange. I can't find that forum post anymore, and I can report that the OTA does NOT fix the issue.
My best guess is that some field in the calendar database is getting set to the wrong value, and the exchange link must not recognize the new event. The strange part is that the stock calendar app works just fine. It's only the 3rd party apps that do not work.