the rules for singles did change.you used to be able to put upto 40 mins of music on a cd single and if you called them mixes of the same track then that was ok with the charts hence born slippy,born slppy nuxx,dark and long,dark train mix etc,etc.underworld seemed to flaunt the rules to give us more when they could but rules don't allow it now !
i thought that the downloads go along way to address this.