Boost.MultiIndex tests are passing for SunOS 5.10 as shown in
http://www.boost.org/development/tests/trunk/developer/multi_index.html
The particular settings of the compiler used for testing are described at
http://www.boost.org/development/tests/trunk/Sandia-sun.html
Do you detect any significant difference?
Another possibility (which I deem highly unlikely) is that boost/multi_index/indexed_by.hpp is missing some include. To rule this out you might want to compile some of the examples at libs/multi_index/example: my hunch is that you'll get the same problem (or equivalent) as above.
Thanks Joaquín. Problem solved. The issue came from "Windows line endings". Installing the "Unix line endings" library fixed the problem. Again, thank you for your help. -Andre