try un-checking and then checking the auto select box then exit out and restart your computer.
Happens to me a lot. Re-booting usually fixes it. Or making sure the element isn't clustered in a group of layers. A lot of time layers in a group are disabled from auto-select so when you click on them it takes you to the group folder not the individual layers.
Check to make sure your Caps lock key isn't on. That one causes the worst problems with tool settings. If you have a wireless mouse change your mouse batteries.
Last edited by SlidingKat; 11-08-2011 at 10:32 PM.
Reason: added more info