[Jack-Devel] firewire ERR (was: JackEngine::XRun: client = pure_data_0 was not run: state = 2 JackAudioDriver::ProcessGraphAsyncMaster: Process error)

I've been trying to fix some audio drop outs issues with Jack and Pure Data
on Ubuntu but couldn't fix it (I had started a thread with the 'was:'
subject) so now I'm giving Sabayon 14.01 a try. Typing $ jackd -dfirewire I
get the following:
jackd 0.121.3
Copyright 2001-2009 Paul Davis, Stephane Letz, Jack O'Quinn, Torben Hohn
and others.
jackd comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details

JACK compiled with System V SHM support.
loading driver ..
libffado 2.0.1-Unversioned directory built Dec 28 2012 19:54:13
firewire ERR: Could not start streaming threads: -1
DRIVER NT: could not start driver
cannot start driver
no message buffer overruns

It's a bit strange as two days ago jack was opening, the 'working
indication' LED on my sound card was turning blue (which is a 'working'
indication) but jack would complain that it couldn't allocate memory, even
though in /etc/security/limits.d there's a "40-realtime-base.conf" file
which includes the following lines:
@realtime   -   rtprio    99
@realtime   -   memlock unlimited

I also tried to compile Jack2 (after I compiled waf) and got a fatal error
during build:
In file included from ../common/JackNetTool.cpp:20:0:
../common/JackNetTool.h:412:30: fatal error: opus/opus_custom.h: No such
file or directory
compilation terminated.

As far as I understand there's a header file missing. Googling it I found
some stuff, but understood that this header file is using other header
files etc. and I'm getting a bit lost here. Any advice on which files to
add to which places?

1389887952.27394_0.ltw:2,a <CAF58LJpPTd--_nH=nnQQPJUMg+hUtTh5qh=eTDhR5vNWR+owYg at mail dot gmail dot com>