There could be MP3 trouble ahead...AOL has been told to stop shipping version 6.0 of its online access software because of a row over who owns the software used in its MP3 playback features. US District Judge A Howard Matz claims there may be a copyright infringement with code owned by PlayMedia Systems - and if proved correct, it could cost AOL Time Warner millions of dollars in damages. In the meantime, the judge has instructed AOL to stop distributing the software. According to the latest reports, AOL subsidiary firm Nullsoft does own a license from PlayMedia for its Winamp MP3 player, but the media giant may have overstepped the mark by using code from Winamp with another player in AOL 6.0. The ruling will not affect AOL 7.0, which started shipping two weeks ago. However, the cost of recalling, retrieving or upgrading version 6.0 software already installed in its user base, in addition to paying damages to PlayMedia, is likely to be high. AOL has already admitted it will lose $39m-worth of pre-prepared CDs and marketing material along, and has pledged to fight the case.