Just got the x0xb0x. I am now stuck.

[antto]

http://www.youtube.com/watch?v=2WvdoH2iHj4
check this, specifically after 02:00 where he explains how to configure the m-audio Venom synth
it uses midi-over-usb, so ignore that detail, the x0x uses midi

basically, in FL, in the midi settings enable your midi output and set the "port" (this is a virtual thing, it only has a meaning within FL) ... set it to 1 for example
then in the "Midi Out" plugin, select the same port number, this way, the midi data from this plugin will be directed towards your real midi interface and out to the x0xb0x

ignore the "bank" and "preset" stuff, in the "Midi Out" plugin you only need to set the port, and the midi channel

in the midi settings, the x0xb0x will not show up as a "x0xb0x" because it's not a midi interface itself
your midi interface would (in my case it's an m-audio delta audiophile 2496 card, and it shows up as "Delta AP MIDI" ..)