We've tested on a OpenSolaris 10/x86 under vmware and a old Ultra-5 station running a Solaris8/Sparc, and runs fine. Your problem could be by another reason, let's try to help you.
If your problem is not the encoding (I've replied you in other threads), just put here your .XML and we will try to help you !
Has anyone been able to get the out of the box Solaris agent to work? I've tried multiple systems that are all running Solaris 10, and none of them work. The agent is configured correctly and it transfers the data to the server, but the data doesn't get processed.