[xwiki-users] Memory Leak detected - can anything be done to rectify?

Hi, just checked through my logs and found this: SEVERE: The web application [/xwiki] created a ThreadLocal with key of type [org.apache.log4j.helpers.ThreadLocalMap] (value [org.apache.log4j.helpers.ThreadLocalMap@2ff7ac92]) and a value of type [java.util.Hashtable] (value [{url=http://wiki.optiplex-networks.com/xwiki/bin/export/XWiki/ResetPasswordRequestClass?format=xar&name=XWiki.ResetPasswordRequestClass&pages=XWiki.ResetPasswordRequestClass}]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak. it's probably the reason my Java instance is so unstable and hogging my systems swap. Can anything be done to sort it?