First attempt to drag backup to Trash always fails
 

Since upgrading I've noticed that the first time I try to drag my backup drive's icon to the Trash (after letting it do its Spotlight thing) it fails (I get the message "Trying quitting applications" etc.). (This is with all other apps closed.)

However, trying again immediately *always* succeeds. It's almost as if there's something which automatically turns you down the first time, like appying for Medicare benefits.

Not a big deal, just a little glitch I noticed and was wondering if others had to.

This is likely Spotlight not releasing the drive... it's not uncommon. If you add the drive to the Privacy tab of the Spotlight Preference Pane it shouldn't happen any more.