Hello all,
It seems I am also having a similar issue as Proximus. I have a Kindle 4 (4.1.1) and successfully jailbreaked it according to
https://wiki.mobileread.com/wiki/Kindle4NTHacking.
I also installed usbnetwork, which is where things get interesting. I tried to use the same workflow as for my Kindle 3 (;debug on, ~usbnetwork, ;debugoff commands on the Kindle) but whilst they worked I couldn't ssh in. I then followed the instructions on the above link under SSH, down to instruction 4 (activating usbnetwork).
Having no success with ssh either, I decided to reboot into Kindle (rather than the Tequila menu) using instruction #9 ("See points 3 & 4 in the Jailbreak section for more details on how to make your Kindle reboot to the main, full system.") This didn't work, however, and I can now only reboot into Tequila!
Before I delve into unbricking, I would be really grateful if anyone can point me in the right direction to reboot into Kindle mode. FWIW, I've tried adding/removing ENABLE_DIAGS, adding device info from xml file, and adding all of the jailbreak files from instruction #1 of the Jailbreak section before reboot, with no success.
Cheers,
R