Thanks for the info. I was getting an error for about a week that the kernel that was installed was too old for whatever Nvidia needs to auto-update its driver, and it then just aborted the install. Once the updated kernel same online, everything installed fine - until the reboot!
One thing I don't get, I have a choice of 3 kernels to boot from but with Compiz deactivated it will not boot with any except the newest one - makes them kinda redundant I would think! I'm sure I can boot with any of them when Compiz is running though.
---------- Post added at 10:44 AM ---------- Previous post was at 07:38 AM ----------
That was a waste of time - I removed the latest kernel but neither of the old ones succeed in booting to a desktop. Although the last update did actually include the latest Nvidia driver, once you remove the kernel, that Nvidia driver is also removed so it's hard to see how that's to blame. And as I've just seen from all the installing/removing I've being doing from the command-line, each kernel has its own Nvidia-compatible driver still installed, so they should work - but they don't!
Looks like I'll be without Compiz for the foreseeable future - having been through the yum log, the second-to-last update was back in June!