Drum machine won't trigger sampler

[link0126]

Hi, just getting started with the TX. I'm finding that everything is working as expected expect that I can't get my SR-16 drum machine to trigger the sampler via midi. I have checked all the settings I am aware of and I can see that the DAW is receiving the signal on the instrument track (using reaper btw). I can also get my keyboard to trigger the sampler like normal but just not the drum machine.

I have had somewhat similar problems in the past with other plugins where some notes from the SR-16 wouldn't sound. It would randomly drop notes and I found it was due to the fact that the midi signals were super quick leaving very short midi notes on the midi track. I solved this problem on playback by quantizing the length on the notes therefore making them all longer like 32nd note length. However, in these cases I could at least get the drum machine to trigger the sounds enough to know what I was recorded and deal with the random dropped note later. In this case, I can't even get a sound from the sampler when using the drum machine.

Any thoughts on this issue? Any way to adjust the sensitivity maybe of the sampler to accept shorter signals or anything along those lines?

Using latest Reaper on OSX 10.10 BTW

Thanks.