The missing class should be in server/?/deploy/jbossweb-tomcat55.sar/naming-resources.jar.
Execute jar -tvf on this file to see if it is valid and contains the class.
How did you unpack the downloaded file ?
Were gzip and tar successful ?
Do you use solaris tar or gnu tar ? Some tar files are only extractable with gnu tar. Don't about jboss-4.0.2.tar.gz.
I know this may be silly but have you upgraded you tar and gzip to the GNU verstion. I know I had to.
The default solaris tar is unusable. You need a gnutar compatible tar.