My browser tries to load a logo from "http://mySubDomain.23video.com/files/sitelogo.gif" and then gives me an error saying it can't be found..
It only happens in Safari right?
Interestingly, the case of the default site logo not existing is actually handled in code (see http://github.com/23/videoplayer/blob/master/src/AppProperties.as lines 101 through 111) but Safari registers the faulty request anyway. We'll be pushing updated versions of our players in the middle of next week -- before then a quick solution is to upload an empty gif as the site logo (under Presentation → Files, name the uploaded file sitelogo.gif.)
Hope this helps,