For the second time, Psystar has failed to meet a deadline to formally respond to Apple's charge that its Mac clones violate Apple copyrights.

Psystar was to have filed its response Monday in U.S. District Court for Northern California, but records show that the court granted the company an extension and that Psystar must now file by Aug. 28. Psystar was originally to have submitted its response by July 28, but received an initial extension to Aug. 18.

The delays could be the result of routine scheduling conflicts, or a sign that the case is more complex than Psystar anticipated. The company's response is the subject of keen anticipation in the computer industry, as it will provide the first public indication of the legal theories that Psystar's attorneys plan to employ in its defense.

Psystar, which operates out of a generic Miami industrial park, has retained the high-profile Silicon Valley law firm Carr & Ferrell. The firm has previously tangled with Apple -- and won. Partner Robert Yorio in 2007 extracted a $10 million settlement from Apple for Burst.com, which claimed Apple violated its streaming media patents. Yorio also helped negotiate a similar $60 million settlement from Microsoft on behalf of Burst.

Apple versus Psystar is a high-stakes case. If Psystar prevails, it could open the door for other PC makers, including major vendors like Dell and Hewlett-Packard, to offer Mac clones. Such a development could undermine Apple's main business model -- which relies on Apple's perceived right to dictate which software products can run on its hardware.

Despite the legal delays, Psystar is showing no signs of backing down. The company last week said that it is "definitely still shipping" its Mac clones. And in further defiance of Apple, Psystar also said it is making Leopard OS restore disks available to its customers.

"Psystar is definitely still shipping Open Computing products and we've introduced our restore utilities to enhance the computing experience for our customers at no extra cost," the company said on its Web site.

Psystar claims its Mac clones cost about a quarter to half of what Apple charges for branded systems. In defense of its clones, the company charges that Apple marks up the cost of the hardware on which its operating systems ride by as much as 80%.

The problem: Apple's end-user license agreement expressly forbids installation or sales of its operating systems on third-party hardware -- a fact that led the company to file suit against Psystar last month and demand that any systems previously sold be recalled.