What happened?

[Rebecca J. Hoffman]

I'm hoping someone can tell me what happened to my iBook last night.

I decided yesterday to back up my hard drive using Retrospect Express. 
I ran Norton Disk Doctor first and it found only minor problems, which 
it fixed. The back up took hours because I was writing to CDs. About 
midnight I was about half done and I decided to go to bed and continue 
in the morning. I clicked the "pause" button and turned down the 
display.

This morning when I got up, I couldn't get the display to come back up. 
When I realized the machine was frozen, I tried to force quit, then I 
tried to do a warm reboot. Nothing. Then I tried the control, option 
and shift keys while hitting the power button. The CD drive (which 
still had the CD I was writing to last night in it) whirred and I got a 
blank grey screen. I hit the power button again to turn the machine 
off, opened the CD drive with a piece of wire and booted up with my 
Norton Systemworks disk. I ran Disk Doctor, including a media check. It 
found bad blocks! It fixed them and right now everything seems to be 
working fine.

What happened? I take it I can't pause the back up process like that, 
but why? I think I'll have to get something else to back up to. Maybe 
one of those little sticks that plug into the USB port. In the 
meanwhile, is it safe to continue backing up on CDs? I'd like to finish 
and have the whole drive backed up.

Thanks!
Rebecca