Actually I solved this problem by updating Bryce and the latest Poser patches, their was some inadvertant bug in Poser not allowing the proper conversion of props in .3ds format. That is what cuased the invalid format errors. Not all of them gave the error, but a good handful of them did. Your best bet to solve this is to Update Bryce to 4.01 with the patch on Metacreations site(be sure to get the updated volumetric presets while your there) and get the latest Poser Patch, When you goto export, you will be presented with the heirachy list, select/deselect what you need, then you will get a second window with 4 options, select the first 3 (not the morph target option) and everything should work out just fine, it has for me so far. FastTraxx