g++ -m64 file.cpp

[James]

Tesing gcc-3.4.3 & gcc-4.0.0 on Solaris 2.8 and 2.9 (64 bit machines)

gcc -m64 file.c => works fine, but
g++ -m64 file.cpp => compiles OK, but erorr in execution.

$ LD_LIBRARY_PATH=/usr/local/lib ldd a.out
        libstdc++.so.6 =>        /usr/local/lib/libstdc++.so.6  - wrong
ELF class: ELFCLASS32
        libm.so.1 =>     /usr/lib/64/libm.so.1
        libgcc_s.so.1 =>         /usr/local/lib/libgcc_s.so.1  - wrong
ELF class: ELFCLASS32
        libc.so.1 =>     /usr/lib/64/libc.so.1
        libdl.so.1 =>    /usr/lib/64/libdl.so.1
        /usr/platform/SUNW,Sun-Fire-V210/lib/sparcv9/libc_psr.so.1

It's complainig about "wrong ELF class".
How do I fix it?
Is this a gcc configure/build problem or something else?
Thanks for your help.

James