It has to do with binary computers not able to represent all decimal numbers correctly. That explains the behaviour of both the Perl and the C program (it's also explained in the FAQ).

As for Solaris, one should realize that Sun hardware has been 64 bits for years, while typical Intel platforms is 32 bits. That doesn't mean you don't have rounding issues on Solaris, you do, but the results may differ.

Abigail