I see there's been a similar discussion before.

http://9fans.net/archive/2009/09/676

But i want to mount inferno from plan9
so that solution doesn't work for me.

if i do

;listen -A 'tcp!*!12345' {export /usr/bfabian &}

that works, but when i do

;listen 'tcp!*!12345' {export /usr/bfabian &}

(so auth isn't turned off)
I get the "bad fversion conversion" error when
i try to mount.