Have you set your seq soft to play this VSTi/DXi?
For ex. on Sonar (MIDI track's properties)
MIDI Track #1
--> I: MIDI Ch #
--> O: DXi/VSTi on use
--> Ch: # on VSTi/DXi
--> Bank: # on VSTi/DXi
--> Patch: # <selected from the drop list>
jiitee
BTW: You seem to have quite expensive software there, compared to your HW --> Wouldn't it be wise to get a sound card that fits better to this quality level

?