I just went through this... :) As Mr. Mongo says, maconverter is still available and does work (there is in fact a link to it in the CuriousLabs FAQ pages for P6). Start it up and drag your props folder in. I set the various options to say "just make me a thumbnail, thanks" and it worked fine. It doesn't actually make the PNG files, but it does adjust the RSRs so that the next time Poser opens the folder, it will make all the thumbnails for you automatically. One thing that confused me on the Mac: if you happen to be a Terminal user, after conversion 'ls' shows all those RSR files as zero-length, which is not actually true, so don't worry. I also heard that the upcoming P6 SR1 is supposed to take care of this and will understand the PC-type RSR files. In the meantime, it's a manual process.