A problem occured in our company several times when using Endnote X.3 - groups disappear. Sometimes just 2 or 3 of them, sometimes even all of them. Is this a special issue of Endnote X.3 - and how to solve the problem? The groups work fine when using X.1 and the information is still available (in X.3) in the record summary.
This is a known issue with some groups from EndNote version X1 and X2 when opened in version X3. We have improved the Group/Group Set capabilities for EndNote X3 for the Macintosh and the upcoming X3.01 patch for Windows. The Windows patch should be available next month.