The legal issues between Apple Incorporated and Open Computer maker Psystar, which arose a few moths ago, have been added a new twist recently, since the latter has dropped its Clayton Act and Sherman Act antitrust claims against the former company, taking the copyright-wise approach.

After Judge William Alsup ruled against the antitrust complaints that Psystar had filed in court, the electronics maker now claims that Apple abused copyright laws with regards to their Mac OS X End-User License Agreement (EULA) and the Digital Millennium Copyright Act (DMCA).

In case the court rules that Apple has misused copyright where the aforementioned are concerned, the company would be deterred from enforcing their copyright, which translates as Psystar being allowed to continue using the Mac OS X Leopard for their Mac clones.

Court filings read that the OS X EULA states the operating system can only be used with Apple hardware, so the Open Computer maker now alleges that Apple has expanded their copyright since it sued Psystar for EULA violation.

As for DMCA infringement, Psystar has stated that Apple went far beyond the protection offered by the Act in their legal actions against them.

On July 3 this year, Apple filed a lawsuit against Psystar in the District Court of Northern California, while on August 28, Psystar Corporation counter-sued the company for anti-competitive practices, monopolistic behavior and copyright misuse.

The case was dismissed by Judge Alsup on November 18.

A ruling following Psystar’s altered claims is scheduled for January 2009.