Hi Ashok, hi everybody,
Thanks for your question! Just downloaded Cytoscape 2.7.0 release, run,
found two problems and how to fix them:
1. Reactome BioPAX L3 files contain 'bp:taxonXref' (BioSource's) property. This should be changed to 'bp:xref' (you can do manually)
(this is a fresh change, since BioPAX L2 v1.0 release, and I suspect this is going to be problem for many new BioPAX L3 files)
2. replace the core BioPAX plugin (biopax.jar) with the attached new one ;)
Let me know if it helps and if you have more questions.
Cheers,
Igor.