Happened to me yesterday when I tried to increase the delegation to my alt account. I was doing it from Steembot tracker tools but I didnt really understand whqt was happening so I gave up.
By the way and apologies if its not relevant, but at one point today, I actually had 108% RC according to Steem supply which I also thought was odd.
Thank god we have you geeks on the case. Enjoy the rest of your weekend mate :-)