Yeah I've had a few crashes here and there. Sharke. One I reported to the bakers (which we chalked up to being an older version of ARC 1) and the other anomalies I experience only seem to happen in Sonar X3 x64.
 
Nothing ever gets me while working on a project though, thank God. My issues come after an export. I've tried the exports with ARC both turned off and left on (though the bus it's on is always not in use) and every 30-40 exports, I'll get an app crash AFTER the export is done. It's never ruined anything for me though thankfully. I wish I could come up with a recipe for it, but it's just one of those "every once in a while" things and it's NEVER happened while using Sonar x86. So that makes me wonder a bit. I also don't use ARC 2 which *may* have something to do with your issue.
 
I don't use the loop thing often but when I do, I've never experienced any drop-outs or inconsistencies. I'll keep an eye out for this and will try a few things with ARC 2 to see if it brings on any crashes.
 
-Danny