but i'll give you some hints on whet i can read from your report above:
try forcing 16-bit and/or 3 periods/buffer; depending on some other settings some audio devices don't run on every sample-rate you throw at it, actually regressing to the one it feels more "confortable" :)
avoid using d-bus; disable it from Setup\Misc\Enable D-BUS Interface and restart;
look at the jackd command line on the messages output if it alll still fails short;
qjackctl version 0.3.9 is pretty much outdated btw.--consider an update to latest v0.3.11.
if things still don't work as expected, try also the JACK FAQ and ultimately JACK Mailing List or the #jack channel on irc.freenode.net.
i'm sorry but i may not be of much help.
but i'll give you some hints on whet i can read from your report above:
hth.
cheers