My 3 day old time machine backup is driving me nuts. It won't stop backing up. I need to restore something and I can't get into the one backup file that has been "in Progress" for 3 days. I have 142 Gb of information on my iMac. Time Machine appears to have already backed up 200 Gb. I stopped it and restarted it two hours ago and it has been "preparing" since then, it hasn't even started to add on to the "in Progress" file yet, it is sooooo slow. What a bummer. Help!