We recommend you apply all updates (however don't blame us if something breaks, you should read up on each update before applying them), they should be applied from behind a firewall on a secure network. We have applied all patches to all of our systems and they are running very smoothly, be sure to read the documents on this link (http://sunsolve.sun.com/pub-cgi/show.pl?target=cobalt/raq550.eng&nav=patchpage) and follow the procedures.
(apply each patch in the correct order - read carefully, at the time this was posted the order was from the bottom up)

** You can use BlueLinQ to install these patches, you need to pick them off in the correct order. We find
it easier and safer to install the updates via command-line as follows:

-First get them onto your Raq 550 in any directory:
	ftp ftp.cobalt.sun.com
	login: anonymous
	password: type_your_email_address_here
	cd pub/packages/raq550
	bin
	prompt -n
	mget *
	exit

-Then install them:
	In the proper order, perform the following for each update as the root user:
	su root	
	password: 
	/usr/sausalito/sbin/pkg_prepare.pl -i -R -f PACKAGE_NAME
		(repeat the above line for each PACKAGE_NAME)