You never answered whether or not you have UAC turned on. I don't have any issues saving content to my runtimes because I told Poser Pro 2010 to create it's content in an external runtime outside of Program Files area because of UAC.

And yeah, it still creates a 32 and a 64 bit runtime in both Program Files and X86 directories. This is awkward when keeping your Python Scripts updated because you have to change files in  both directories if you use both 32 and 64 bit and switch back and forth as I do.