Right, my previous thread and the sharing of projects reminded me. For as long as I can remember, this happens when I try to render offline in REAPER with offline rendering quality set to Sinc128 and the "Inform plugins of offline rendering state" option checked:
Some really nasty clipping going on there. Sinc64 and lower resampling modes work fine and sound great, so I haven't really bothered reporting this. But I figured as you [elcallio] now have a project of mine, it would be interesting to know if you encounter the same issue or if it's simply a problem on my end for some reason.