I don't know how to write this up as a bug report, because I don't think I can make it reproducible without making a large project.
Anyway...I suspect there's something up with Reaper's Plugin Delay Compensation and it's interaction with Reainsert.
In particular, I'm experiencing this issue right now:
http://forum.cockos.com/showthread.php?t=134898
I'm posting over here because it's probably more appropriate.
As I progress through a project and start using more and more complex routing and inserting hardware via Reainsert, Reaper gets more and more flakey in starting playback. In some cases, it's just a miscalculation in PDC resulting in out of sync audio. In others, it's a completely jumbled mess of crackly, slowed down, distorted audio, in some cases, I end up with excessively high RT CPU usage and an unlistenable playback.
Often times, all that's needed to remedy this is a simple stop/start of playback, and Reaper calculates everything fine and plays back normally. If I jump forward or backward in time, it's a total crap-shoot if Reaper will rebuffer properly. When it doesn't, out of sync audio or crackly distorted and slow playback is the result. Again...Simply stopping and restarting playback resolves the issue. Sometimes I have to stop/restart 2-3 times to get there.
I predominately mix alone...But earlier this week I had a guest with me. Fortunately we were just listening to some references, but it really struck me this morning, There's no way I could mix the way I like with Reaper in front of others.
Client, "What's wrong?! What happened there? Is my track hosed?!"
Me, "Nah...Hold on...Reaper isn't playing back right...Let me stop and restart playback. There...That's better."
30 seconds later we jump to another section of the song and it flakes out again.
This isn't productive. At worst, it means I can't do something I want to do. At best, it just interrupts my workflow for a second. But even that's bad.
From a client perspective...It makes me look unprofessional. "Man...His setup is really flakey! We didn't lose anything and the mix is alright, but it glitched the whole session."
Reainsert has totally improved over the years. I seldom if ever get the buffering loop of doom anymore. It still doesn't work right in complex projects though. I know that myself and many others would like to be able to depend on it more...But it's just flakey.
Thank you in advance for any consideration of this issue. I'm more than willing to provide an example session or two.