CentOS

I've been using Centos for a long time now, and currently using CentOS 6.2 since it was released. I love CentOS, but I seem to recall some real nightmares on earlier versions with NSS. My server would stop halfway through a reboot and as we use it mainly for running our webservers we were offline for 2 days before we found that after updates which installed NSS, the server just stopped rebooting waiting for input. In the end I just disabled NSS entirely.

I see this morning there are new NSS updates, so I'm wondering if installing these is going to give me similar problems, I can't find any documentation on what it does, how to configure it and what to expect after it is configured. I know my way around Linux, but I'm certainly NOT a 'guru'.

Can some kind person point me at some documentation or give me some info on what to do and what to expect if I install these new updates?

I have applied the NSS updates to a number of systems without incident, nor have I seen any reports of problems.