That's just it, on ANY hard drive shoved in the thing, it just hangs like that if I try to install FLP. the mup.sys hang is prevalent across all drives tried, even an SD card in a CF adapter in a 2.5" adapter just for the giggles of trying. the ISO is good, md5 checks out where applicable, as are the drives used... processr.sys wouldn't be the issue per-se, it has to be the lack of the transmeta.sys file, possibly. I've confirmed at the very least that the transmeta.sys file is nowhere to be seen anywhere on this disc, and that's troubling. As for why it doesn't exist, probably because Microsoft didn't see the Transmeta Crusoe or Efficeon CPUs to be in anything that a "corporate partner" would have so many of in service that they needed to include it.
I know for a fact I can shove some files from the existing, and completely working XP install onto a CD to give that a shot while in the FLP setup command prompt... I forget if said system has access to flash drives during the setup process, but I'll try that first and a CD later, when I'm not feigning sleep. that by itself just might work. I'll try first by just adding the files, but if there's some file I need to diddle with to make the system aware it needs to parse transmeta.sys at boot time as well, then I'm all ears.
in other related happenings, I found some old mailing list archives from around 2008 of FLP and Transmeta CPUs being talked about on Sunhelp in regards to a Sony Picturebook, but no verification of installation.