Yamaha DTXpress/DTXplorer/DTXtreme

hello from CT!
if someone would please help me; i'm stumped.
I've just added the Midiman 2x2 so I can track both my Roland s-10 
MIDI-controlling kybrd (w/a KORG X5DR sound module) and DTXpress.
here's what i've got: 
MIDI out from the s-10 into the snd module. 
out from the module into in-A of the 2x2. 
out-A of the 2x2 into s-10 kybrd. 
DTXpress out to in-B of 2x2.
out-B of 2x2 into DTXpress.
what am i doing wrong?
i chose the ports in PA9.
do i need to set something in the DTXpress? For example, MIDI 
functions in the sound module only in GLOBAL MULTI mode. (what does 
THAT mean anyway??!)
H E L P   P L E A S E ! !