I've tried to prepare a USB stick with haiku-nightly-hrev50321-x86_gcc2_hybrid-anyboot, following the instructions for Linux via a terminal:
System 1 is a Gigabyte GA-6OMM7E motherboard, has Plop built in to the BIOS, see https://www.plop.at/en/bootmanagers.html
Note! This system has booted Haiku USB before, as with for example revision 47380, so neither the boot manager nor the hardware is believed faulty
System 2 and 3 both boot USB via the usual BIOS boot device selection, nothing unusual there:
System 2: Fujitsu Siemens Amilo PA 1510 - fails, says "Failed to load OS, press any key to reboot" with USB plugged in
System 3: White box PC with Athlon XP based motherboard Biostar M7NCD, only one that booted
Any ideas? Yes, I'm retrying with the current nightly.
Oh and yes, the SHA256 sums posted in the download area match, so no corupt files here