Shit, I completely forgot that I'd asked you to post that. Sorry for the late reply.
Anyway, it plays fine for me, in Reaper, through Steven Slate/Kontakt, so I'm going to suggest it's either your VSTi or how you've got everything set up.
- What VSTi are you using?
- Are you using multiple tracks in any way, and if so, how are they routed together?
- Are there any effects in the chain prior to the VSTi that might be "eating" the MIDI? If you have the MIDI item on a separate track (I do, so I might as well ask), are there any effects on it?