Is the drum map the difference between your X3 and Platinum setups or is it not affecting X3? I added a drum map to my test project, and still didn't encounter any problems.
 
Any chance your drum map is routing some notes to an unused note number in the kit? Is it always the same note number/kit piece/articulation getting "dropped"?

brundlefly
Is the drum map the difference between your X3 and Platinum setups or is it not affecting X3? I added a drum map to my test project, and still didn't encounter any problems.
 
Any chance your drum map is routing some notes to an unused note number in the kit? Is it always the same note number/kit piece/articulation getting "dropped"?

The drum maps are the same between X3 and Platinum. It seems to be a combo of using a humanizer AND a drum map. However, once I disabled the drum map with the humanizer still enabled, the dropped notes stopped happening and everything played fine, even through several playthroughs. This leads me to believe it's an issue with drum maps and MAYBE not necessarily with the humanizer. It wasn't specific notes that were dropped, it was random with each playthrough.
 
What's interesting is that no matter what midi buffer I was using, I still got a dropped note. However, the number of dropped notes seemed to have "threshold". It happened a lot at lower buffers (~ 250-500). The more I raised the buffer, the less the dropped notes were happening. However, at 2500 and ANY higher number, I was still getting a FEW dropped notes, but not as bad as the lower values.
 
This was until I decided to disable the drum map late last night and see what happened. Low and behold, the dropped notes stopped occurring, even with the humanizer still enabled. I think I'm close to getting to the bottom of this.

I'm getting a lot more dropped notes on an Addictive Drums midi track than I did in X3e - prepare buffer doesn't have any effect. Perhaps this is because  of opening an X3e project in Platinum? 

I think it must have something to do with all this bleeding edge hardware and operating systems everyone is running.   My hairy old quad core with Win7 just keeps plugging along. Anybody have a sample project to post using only bundled FX and synths?
 
 

MagicMike
I'm getting a lot more dropped notes on an Addictive Drums midi track than I did in X3e - prepare buffer doesn't have any effect. Perhaps this is because  of opening an X3e project in Platinum? 

If you're using a drum map, try disabling it and just routing the midi track directly back to AD. It worked for me, I suggested it in someone's post and it worked for him too.

Hi Vern, 
yes I'm using a DrumMap - I'll try what you suggest. Maybe re-create the DrumMap in Platinum?

I found a fix! I went back to X3E - no dropped notes.
 
I'll continue to work on projects that were created in X3E and when ready will bounce my midi drum tracks to audio. I'll then open the project in Platinum to gain the benefit of mix recall etc.