Oh, my English!
I do such experiment:
I use plpbt.img from native archive which I download from your site - 5.0.12 version. I boot it from HD with GRUB4DOS, with maping for memory, and try to boot CD disk making with GRUB4DOS - no correct boot, GRUB from CD says on command 'root': corrupt partition table. And do the same using 5.0.8 version - all is OK.
PS. From the point of view USB - are this version 8 and 12 different?
5.0.11.2 - OK
I re-flash my NetCard with 11.2. as you say change config, all is OK with CD. Now I must try USB, but I have not any USB device.
ps One little idea - it's be usefull to have option to see and boot logical partition too