in reply to Help: Writing to largefiles
I just had this same problem. The answer turned out to be that Perl was incorrectly compiled without "-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64". I was able to see this in the output from perl -V, in the ccflags value. Once I recompiled with a better compiler, the Configure script was able to add these for me, then 64 bit file access worked right.