@DRNKMNKY:
Huh. Okay, so that's not just my old K2i getting creaky, I think I know what triggered the errors 0003... Will fix. (FWIW, the installation was successful, even if it doesn't look like it, I don't know how the 0003 error screen looks on the K4, but on previous devices we can hit a key (R) to continue booting, and it works

).
Err, wait, you mean that with v0.41.N, with the default settings (USE_VOLUMD false), it *doesn't* pop the USB Drive Mode screen?
Yeah, I can confirm that, there's a timing issue when using volumd, everything's up, but on volumd's terms (ie. on 192.168.15.244). I'm testing a workaround for that, too.
The setting USE_VOLUMD sets seem to be permanent, which *might* explain the 'sticky' USB Drive Mode screen, since nothing's reset it with what you did.... What you *can* try is to re-enable USE_VOLUMD over USBMS, eject, and trigger ~usbNetwork manually (might need to trigger it twice, actually, if I followed things right). You should then end up with your Kindle in usbnet mode, at best on the right IP, at worst on 192.168.15.244.