Damn m0r, didn't mean to incure your wrath. But what I said has allways been my experience.
I posted some pics down in the shameless screenshot thread and first they were just linked directly to the image. The same error as above occured, after reading the terms of use I realized that they don't allow linking to content unless it's from a page in your site.
Thus, I put my images in the .html for my site and it worked flawlessly. Weather GeoCities protection is 100% or not, i dunno, but I do know that if they are embeded in the .html the images will work 100% of the time.