How long can a single trial go on for? Well apparently Apple and VirnetX want to find out, as yet another decision out of a United States appeal court will undoubtedly fuel things along.

This particular legal battle between the two companies has been going on for nine years, and while there have been close call resolutions in the past, including Apple being forced to pay millions of dollars in a patent dispute, things just keep trucking along anyway. For example, the latest decision (via Reuters) from the U.S. Court of Appeals for the Federal Circuit has vacated the latest appeal, forcing the decision back to a lower court in Texas.

This decision is even more complicated than it probably needs to be. Specifically, it’s a bit of a mixed bag for Apple, because the appeals court ruled only a partial reversal when it’s all said and done. The court confirmed two cases of patent infringement, and reversed two others.

The court reversed the jury’s infringement finding on two other patents, however. Based on that ruling, the court sent the case back to a Texas judge for further proceedings.

The Texas judge must consider whether to hold a new damages-only trial or to recalculate damages without holding one, the appeals court said.

This is just one of two legal battles going on between VirnetX and Apple. This one saw Apple having to pay upwards of $503 million in patent infringement. The other, which also has a series of appeals in the works, has already ruled against Apple, telling the company to pay $440 million in that patent case.

As far as the patent war going on between the two companies, the patents in question relate to virtual private networks (VPNs), FaceTime, and iMessage.