According to the lates 10Q there are two risk factors that I don't remember seeing in past filings. TPL is protected

We May Be Required To Fund Our Joint Venture’s Legal Costs. (NEW)

On March 20, 2013 TPL filed a petition under Chapter 11 of the United States Bankruptcy Code. While TPL’s petition does not affect the licensing agreement between PDS and Alliacense, PDS has incurred increased third-party legal costs as the litigation with HTC Corporation, and Acer, Inc., in the U.S. District Court, and the actions with the ITC Investigation No. 337-TA-853 progress. If PDS does not receive sufficient licensing revenues to pay these expenses, we may be required to pay these expenses. In the event the cost of the U.S. District Court and ITC Investigation actions exceeds our ability to fund these efforts, our options for additional sources of financing may be limited.

We Are Dependent On A Single Law Firm To Defend And Enforce Our Intellectual Property Rights. (NEW)

A single law firm has been engaged to defend and enforce our intellectual property rights. Any significant interruption in their services, or the loss of their services for any reason, would have a material adverse effect on our ability to defend and prosecute such lawsuits and, therefore, have a material adverse effect on our business, financial condition and result of operations