There doesn't appear to be any sort of file path issue on my end. Arrowchat is installed in a subdir of my forum (where the instructions tell you it should be) and Sleek is installed where all of my other AC apps are installed and where it has to be installed for Arrowchat to see it in the admin panel. That problem probably isn't related to nginx as Jason pointed out he was having file path issues as well.
And no, the player does not move through the playlist in the XML. The behavior I described where the player won't move to the next song in the playlist unless the repeat option is enabled happens even on your demo site.
http://0m3ga.net/forumAlso the issues with the double slashes in file paths are apparent in your demo site's config as well:
http://0m3ga.net/forum/arrowchat/config.xmlI'm guessing your script pulls the path of AC from AC's settings, which forces it to end with a trailing slash.
Caching is handled by browsers but you do have control over caching directives through your code.
Yes, I got the player to work eventually but it was clearly not in a working state as it's sold. There was no notice on the store page that says "some assembly required" nor do you list exactly what the "right conditions" for it to work properly are. I'll happily give it a better review if you fix the bugs I pointed out. The review and my bug report are not flames and are entirely constructive. I am looking forward to the new version you're creating.