Solaris 10 ipf upgrade - a good idea?

[Chris Ross]

  I've seen numerous discussions about updating the ipfilter
(and pfil) in the release version of Solaris 10.  But, I don't
recall seeing *why* people were doing it.

  Is there a known flaw or deficiency in the 4.0.2 (which Darren
notes is actually closer to 4.1) that ships with the release
version of Solaris 10?  Is there a security problem?  Just new
features added?

  Perhaps Darren is the best person to answer this, but if anyone
else knows what the pro's and con's are of doing this, I'd
love to hear details.

  Thanks...

                            - Chris