So after a few soft rejections, which eventually led me to deleting the item from the cue, I have finally discovered my problem. For some reason, Reaper is not handling UVI mixdowns. It does not matter if I render it in the track and then mix it down, or if I mix it down straight from the Midi-plugin (without audioizing the track). I have been using UVI Complete Piano Collection a lot, and I love it, but whenever I try to create a track, there’s always artifacts (cracks, pops, strange stutters). I thought it was a problem with UVI, but then I tried going back to Cubase, and no problems whatsoever.
It’s kind of funny. About 3 months ago, I made a go for Cubase after buying a UR22. I opted out of it and remained with Reaper because I was way more familiar with Reaper, and just didn’t want to go through the learning curve with Cubase. After returning to Cubase now, I noticed that it seems really familiar and intuitive to me. I understand it better, and I feel more comfortable using it than I do using Reaper. Very strange.
Due to this, I have decided to make my transition completely over to Cubase.