sysinstall(8) uses the local system release string (kern.osrelease)
	to construct the path to the distribution directory on an FTP site.
	However, it doesn't allow for a patchlevel `-pXX' that may appear
	in the release string.  Therefore sysinstall(8) fails to locate
	distribution files (in particular, packages) on FTP if a patchlevel
	is present in the local release string.

	This may appear confusing to beginner users, who are the primary
	consumers of sysinstall(8) as a system maintenance tool.

Fix: Since the system patchlevel doesn't affect sysinstall(8) actions
in any way, we can just strip it off completely as follows:
How-To-Repeat: 
root@bsd:~#uname -sr
FreeBSD 4.9-RELEASE-p11

root@bsd:~#/stand/sysinstall
...
+------------------ User Confirmation Requested ------------------+
| Warning:  Can't find the `4.9-RELEASE-p11' distribution on this |
| FTP server.  You may need to visit a different server for       |
| the release you are trying to fetch or go to the Options        |
| menu and to set the release name to explicitly match what's     |
| available on ftp.freebsd.org (or set to "any").                 |
|                                                                 |
| Would you like to select another FTP server?                    |
+-----------------------------------------------------------------+
|                      [ Yes ]         No                         |
+-----------------------------------------------------------------+