When you go to make the PRC book select Make Palm or Pocket PC book. Then the filetype should be [b]Mobipocket Reader[/i] and the device I select is Palm (color).
For making IMP books, Select REB1200, GEB1150/2150, Softbook. If you then get a requester asking Do you want to switch on Multilang support?, select no. The device you want to select is Geb1150 and you want to make sure No paragraph separations is selected as well. Then you can alos post IMP and PRC books of all the books you've posted in LRF.