ISI has changed their file format. In order to load ISI files you will have to download and install this\ plugin. For more information how to download and install plugins click here. More information on the ISI file format can be found here
Science of Science (Sci2) Tool User Manual, v0.5 alpha Updated 3.28.2011
Project Investigators: Katy Börner and Kevin W. Boyack (SciTech Strategies Inc.) Programmers: Micah W. Linnemeier, Russell J. Duhon, Patrick A. Phillips, Chintan Tank, and Joseph Biberstine Users, Testers & Tutorial Writers: Katy Börner, Hanning Guo, Scott Weingart
Cyberinfrastructure for Network Science Center School of Library and Information Science Indiana University, Bloomington, IN http://cns.iu.edu