Hi, I've just downloaded the Sling code and I found that the class org.apache.sling.obr.Repository instantiates DateFormat implementations statically and uses them in instance methods which are not synchronized. I'm not familiarized with the code, I'm not sure whether the access to those methods is synchronized somewhere else, but if they are not the the DateFormat will generate wrong string representations of the date under heavy load.
see http://java.sun.com/j2se/1.4.2/docs/api/java/text/DateFormat.html br, edgar
