In my case it was not an upgrade, i had a working install ot Jasager 1 before that, did a fresh reflash from step 11 from the Wiki, then followed the guide from http://wiki.hak5.org/wiki/Fon_Jasager_Install_v2_1 , then it hung at "Starting Jasager" exactly as Darren's post. The Fon was responding to pings, scanned it with nmap and the ports (80,22 etc) were all open, tried to ssh in but the connection hung, fired up Wireshark, tried ssh again, the tcp connection was established successfully but there was no data comming from the fon, same with the web interface, the tcp connection succeeded but the web server didn't send even a single byte of data. After i unplugged it and booted it again all was working fine.