SONAR 8 and Roland SPD-20 ?

[stixs]

Hi all
I am new to the forum and hope someone could help me with a setup question.
1st my equipment: Roland V-Drums TD-20, Roland SPD-20, Edirol PCR-30 Keyboard, M-Audio Delta 192 sound card, M-Audio Midiport 4x4, SONAR 8 Studio and a fast computer.
2nd my connections: My keyboard is connected directly to the M-Audio delta 192 sound card, my V-Drums and SPD-20 are connected to the M-Audio Midisport.
3rd my problem: I have no problems with my V-Drums and the keyboard. I can record with SONAR with no problems.
My question is, I am trying to trigger sounds with the SPD-20 using Rapture and Dimension Pro. I open a MIDI track in SONAR and insert a Soft Synth (Rapture) but when I hit the SPD-20 pads, the sounds are cut off really fast and do not sound right?
Yes I have read the SPD-20 manual and I am stuck.
Can someone please help?

Thanks in advance.