I love Time Machine. I've been in the habit of doing full disk backups, but that won't save me from accidentally deleting a file unless I notice before the full disk backup is made. With time machine I'm protected. I still do a full disk back up from time to time so that I have something to boot from and then restore from Time Machine on if my main drive goes belly up.
One thing I've noticed: most mornings when I close up my laptop and take it with me for the day, the Time Machine backup disk won't eject. I get the standard "this disk is in use and cannot be ejected" warning. I'm confident the only thing using the disk is Time Machine. It seems that Time Machine makes it hard to eject disks.
This wouldn't be so bad on a desktop, but on a laptop, it's a pain. I hate just unplugging and getting the red stop sign warning about damaging the disk. Maybe more my paranoia than anything, but I like to avoid it.
I've found that forcing an unmount after trying the regular eject always works:
sudo umount -f /Volume/Phil\\ Backup
Obviously your volume name is probably different and no, I didn't forget the "n" in "umount". Note that name of my backup drive is "Phil Backup". Why it doesn't work before an eject, I'm not sure. Still, it avoids the warning.
To make this easier, I made an alias for it in my .bashrc file:
alias u="sudo umount -f /Volume/Phil\\ Backup"
Now, just typing "u" at the command prompt (which I've almost always got ready) will unmount the disk. Anyone have a better solution or am I the only one dealing with this problem?