Other that the latest Optifine, I am not using any mods, but I thought that, since Optifine is technically considered a "mod", that negates problems with MC being reportable to Mojang. Please correct me if I am wrong.
I will submit the report to Mojang at the address you provided, and see what happens. Optifine or not, the doubling problem seems to be an anomaly, and I think they should know about it. It is annoying, and dampens the enjoyment of my game (especially the ubiquitous crafting tables!).
Thank you very much for responding to my request for help.