Hi Peter, I can't tell what the cause of the problem is from the information you provided. NetCDF-3.6.2 builds out of the box on our AIX 5.1 platform with xlc, xlf, xlf90, and xlC, with no errors during the build and "make check". We might be able to diagnose the problem if you can send us the information requested here: http://www.unidata.ucar.edu/software/netcdf/docs/netcdf-install/Reporting-Problems.html Thanks! --Russ Russ Rew UCAR Unidata Program address@hidden http://www.unidata.ucar.edu Ticket Details =================== Ticket ID: TYC-568521 Department: Support netCDF Priority: Normal Status: Closed