I typically find that pasting the error message into a google search turns up useful information. In this case, it turns up this thread, but also a similar question on another forum last year that got some pretty good answers. Rather than plagiarize those answers, here is the link:
bind: Address already in use messages ? - LinuxQuestions.org
Unfortunately, the proximate solution was the windows solution -- reboot. I don't like that on Solaris, and for a critical server it often can't be done. But there is also some more detailed information in that thread that would help track down the cause of the problem.