Rapture session drum volumes question

I just started to construct a drumbeat in rapture session. First three bass drum hits(c3) then two snare hits(e3) then two more bass drum hits(c3).Right off the bat I notice the second set of bass drum hits are much quieter than the first. After a bit of experimentation I realize that if I take out the snare hits the kick hits all stay the same volume but as soon as a snare hit occurs the subsequent bass hits are much lower in volume - I even tried upping the velocity of the subsequent kick hits and they don't seem affected by the velocity change - still quiter than pre-snare kick hits. I'm in Rapture Session using d-pro bank 05-drums. Is that dimension pro? I think it came with the Sonar Platinum. All of the drum banks - dry kits and wet kits are all exhibiting this behavior. How could a second note playing affect the subsequent volume of a previously played note and cause subsequent playings of the first note to be lower volume than the first time it was played??

To clarify, I am entering the notes via prv - usually use addictive drums but i have that installed at my studio and I think you can just have them on one computer(??) Sometimes I'll get a song going at home with a midi track or two. I have never encountered this behavior before. Are the cries of Sonar midi sucks valid?