I also am having this issue on about 6 different sites. I’ve done everything mentioned. I’ve tried different computers, IP addresses, web browsers – it makes no difference. My host spent 3 days trying to figure out if it was something on his end. The ONLY thing these sites have in common is WordPress. They are on different themes, some are brand-new and others have been around. I finally reverted back to 3.4.2 because no one can figure what is going on. Any help would be appreciated so I can update back to 3.5.1.
