I'm getting rather panicky now. I was trying to connect to a network drive on my MacBook when I got a beachball. Nothing would work, not even force quit would come up. So I held down the power button until it went off, and then switched it back on again. It got as far a blank blue screen but no further. I tried it again and this time it didn't get past the grey screen with the Apple logo and the spinning wheel. So I took the battery out, unplugged from the mains and held the power button down for over 10 seconds. Then held down Command Alt P R to reset the PRAM. That didn't solve anything. This is the first reboot since some security updates on Saturday past. I'm running Leopard and it's an oldish Macbook, Core 2 Duo with 2 x 2 GB sticks of RAM. Applecare has expired. Any suggestions anyone? This is very scary.