There's a big fix for OWL today. There were some mysterious times when pages that I thought I was changing were getting reverted. I thought originally that this was a glitch from me btsync-ing between my laptop and tablet. Or maybe my attempts at doing background synchronization between the browser localStorage and the server were failing.
Nothing seemed to completely eliminate this intermittent problem. But today I realized it was much simpler. I was basically using web.py's "static" file serving to pull the OPML files off the server into Concord. But "static" is meant for static files (doh!). The browser was caching them. (Maybe because of some header web.py was putting out.) Anyway, I just changed the server to reading the files into memory and spitting their contents out, just like any other dynamic web-page, and the problem looks like it's gone away.
I'll keep an eye out, but I think that was it.