well i am afraid my knowledge of poser is limited and i cannot help you to solve this :( I intensively make them tested on a poser propack, without trouble. Poser 5 seems to be lmuch more complex and less tolerant. for the bad preview thumbnails it seems either my png or my rsr are corrupted in the present package (though i used p3do wuith plugin) but you can delete one kind (i thing deleting png will work better) and "voila" :( sorry not to be able to help you more :( i still am interested into any feedback and "poser guru" advice and opinion on this...