The row between file-swapping services KaZaA and Morpheus escalated today after KaZaA made its most blatant attempt yet to poach users from its rival.

KaZaA today launched software designed to help Morpheus users 'migrate' to its service. StreamCast Networks, which runs Morpheus, was forced to shut down last week after software provider FastTrack upgraded the P2P file-sharing program it licensed to Morpheus. Morpheus no longer has a licence for the software.

KaZaA has, rather sneakily, used a period when StreamCast is in a bind over its software licence to pinch users from the service, issuing an 'easy' migration package and adverts. StreamCast hit back by accusing KaZaA's software of having security holes, even though until last week it used the same ware.

The situation isn't helped by the fact that KaZaA and FastTrack were, until very recently, owned by the same person.

In a statement on its website StreamCast blamed FastTrack's software for a recent denial of service attack on Morpheus servers.

"Since it appears that the attack on your computers came from… FastTrack-Kazaa software, we have opted not to continue with this P2P kernel," ran a statement on StreamCast's website. "We believe [KaZaA's software] to have the ability to access your computer at will and change registry settings."

KaZaA has rebutted the claims. "We so genuinely don't want to be in a fight [with StreamCast]. We want them to be successful because that provides a good business environment for us too," she said.

In a bid to quell a mass exodus of its users to KaZaA, StreamCast Networks rushed out the new version of its software today. Morpheus Preview Edition is based on the open-source Gnutella network instead of FastTrack's software.

Until last week KaZaA, Morpheus and another service, Grokster, were all powered by FastTrack. But PC Advisor has been told that StreamCast feels wronged by FastTrack's upgrade to its new version and new licensing.

The upgrade resulted in incompatibility between new and old versions of the software. This in turn caused communication problems between key Morpheus servers sitting on a communal network with those of KaZaA and Grokster, forcing the shut-down.

FastTrack is owned by Niklas Zennstr"m. Zennstr"m ran KaZaA in Europe before selling it to Sharman Networks in Australia in January. KaZaA and StreamCast were previously seen as allies, but the news appears to hint at a deepening rift between the two services.

Morpheus has been plagued by mishaps over the past month, including reports of another security hole that allowed hackers to browse personal files on Morpheus users' hard drives.