Hi Chen, Sorry to have taken so long to reply. We can't duplicate the problem you are seeing. We were able to build netCDF-4 on a 64-bit AIX 5.1 platform (the most recent we have access to), and the output from the configure and make steps are here: http://www.unidata.ucar.edu/software/netcdf/builds/4_0/zasu_AIX_netcdf-4.0_64_2008-06-29-13-42.txt The NF90_INT64 type is supposed to be different from the NF90_INT type, but I don't think we test for that, so it's possible you have discovered a bug. Do you have a small program demonstrating the problem that I could use to try to reproduce the problem on our AIX platform? --Russ Russ Rew UCAR Unidata Program address@hidden http://www.unidata.ucar.edu Ticket Details =================== Ticket ID: YRL-141737 Department: Support netCDF Priority: Normal Status: Closed