Unable to checkin File in SkyDrive Pro - Excel Web App

I have an Excel spreadsheet that I was editing in Safari. I closed it and then opened it on another computer and noticed that two people were editing it. It was myself on two computes. I've opened it in the same browser on both of the computers, edited it in the same browser and then closed it but it still shows that two people are editing it. Any suggestions how to force a checkin? I don't care if I loose any data or not.

Thanks,
Dave